HK1175315A

HK1175315A - Stepping motor control circuit and analog electronic timepiece

Info

Publication number: HK1175315A
Application number: HK13102517.5A
Authority: HK
Inventors: 间中三郎; 小笠原健治; 佐久本和实; 本村京志; 清水洋; 山本幸佑
Original assignee: 精工电子有限公司
Priority date: 2011-06-01
Filing date: 2013-02-28
Publication date: 2013-06-28

Description

Stepping motor control circuit and analog electronic timepiece

Technical Field

The present invention relates to a stepping motor control circuit using a secondary battery as a power source and an analog electronic timepiece using the stepping motor control circuit.

Background

Conventionally, the following analog electronic timepiece has been developed: this analog electronic timepiece uses a secondary battery as a power source, and the secondary battery is charged by a power generation unit such as a solar cell.

A conventional analog electronic timepiece having a power generating unit prepares a plurality of types of main drive pulses P1 having different energies from each other, and drives a stepping motor by switching (pulse-up) the main drive pulse P1 to a main drive pulse P1 having a large energy in accordance with the voltage of a secondary battery (see, for example, patent document 1).

By driving the stepping motor with the main drive pulse P1 switched to energy corresponding to the voltage of the secondary battery in this manner, the stepping motor can be rotated even when the voltage of the secondary battery is reduced.

However, when the main drive pulse P1 is switched only according to the voltage of the secondary battery, there is a problem that the consumption of the secondary battery is rapidly increased because the stepping motor cannot be rotated by the main drive pulse P1 and is driven by the correction drive pulse P2 having a larger energy than the main drive pulse P1.

On the other hand, the following inventions are known: a plurality of main drive pulses P1 are prepared, and as the energy for driving the stepping motor reaches a limit and the drive margin becomes smaller, the main drive pulse P1 having a large energy is switched (pulse-up) in advance to drive the stepping motor. By combining this invention with the invention described in patent document 1, the main drive pulse can be switched according to the secondary battery voltage, and the stepping motor can be rotated by switching to the main drive pulse having an energy margin according to the rotation state of the stepping motor.

However, although the stepping motor can be driven, the main drive pulse is pulsed up at an early stage, and thus there is a problem that drive energy is wasted.

[ patent document 1 ] Japanese patent application laid-open No. 62-238484

Disclosure of Invention

The present invention has been made in view of the above problems, and an object of the present invention is to prevent the occurrence of the non-rotation and suppress the energy consumption by driving with the main drive pulse corresponding to the voltage of the secondary battery and the rotation state of the stepping motor.

According to the present invention, there is provided a stepping motor control circuit comprising: a secondary battery as a power source that supplies at least electric power to the stepping motor; a voltage detection unit that detects a voltage of the secondary battery; a rotation detection unit that detects a rotation condition of the stepping motor; and a control unit that drives the stepping motor in a 1 st mode or a 2 nd mode, wherein in the 1 st mode, a drive pulse corresponding to a rotation condition of the stepping motor is selected from 1 main drive pulse and a correction drive pulse having energy larger than that of the 1 st main drive pulse to drive the stepping motor, in the 2 nd mode, a drive pulse corresponding to a rotation condition of the stepping motor is selected from a plurality of main drive pulses and a correction drive pulse having energy larger than that of the plurality of main drive pulses to drive the stepping motor, and the control unit switches to one of the 1 st mode and the 2 nd mode to drive the stepping motor according to whether or not the voltage of the secondary battery detected by the voltage detection unit exceeds a predetermined switching voltage.

Further, according to the present invention, there is provided an analog electronic timepiece comprising: a stepping motor that rotationally drives the time hand; and a stepping motor control circuit for controlling the stepping motor, wherein the stepping motor control circuit is configured by the stepping motor control circuit.

According to the stepping motor control circuit of the present invention, by driving with the main drive pulse corresponding to the voltage of the secondary battery and the rotation state of the stepping motor, it is possible to prevent the occurrence of the non-rotation and suppress the energy consumption.

Further, according to the analog electronic timepiece of the present invention, since the driving is performed by the main drive pulse corresponding to the voltage of the secondary battery and the rotation state of the stepping motor, it is possible to prevent the occurrence of the non-rotation and to suppress the energy consumption, and thus, it is possible to perform the accurate needle movement.

Drawings

Fig. 1 is a block diagram common to analog electronic timepieces using a stepping motor control circuit according to embodiments of the present invention.

Fig. 2 is a timing chart common to the stepping motor control circuit and the analog electronic timepiece according to each embodiment of the present invention.

Fig. 3 is a determination diagram common to the stepping motor control circuit and the analog electronic timepiece according to each embodiment of the present invention.

Fig. 4 is a flowchart of a stepping motor control circuit and an analog electronic timepiece according to embodiment 1 of the present invention.

Fig. 5 is a flowchart of a stepping motor control circuit and an analog electronic timepiece according to embodiment 2 of the present invention.

Fig. 6 is a timing chart common to the stepping motor control circuit and the analog electronic timepiece according to embodiment 3 of the present invention.

Fig. 7 is a determination diagram common to the stepping motor control circuit and the analog electronic timepiece according to embodiment 3 of the present invention.

Fig. 8 is a flowchart of a stepping motor control circuit and an analog electronic timepiece according to embodiment 3 of the present invention.

Description of the reference symbols

101 an oscillating circuit; a divide by 102 circuit; 103 a control circuit; 104 a main drive pulse generating circuit; 105 correcting the drive pulse generating circuit; 106 irregular needle-moving pulse generating circuit; 107 motor drive circuits; 108 a stepper motor; 109 an analog display unit; 110 a rotation detection circuit; 111 a detection section discrimination circuit; 112 voltage detection circuit; 113 a secondary battery; 114 solar cell.

Detailed Description

Fig. 1 is a block diagram of an analog electronic timepiece using a stepping motor control circuit according to an embodiment of the present invention, and is a block diagram common to each embodiment described later, and shows an example of an analog electronic wristwatch.

In fig. 1, the analog electronic timepiece includes: an oscillation circuit 101 that generates a signal of a predetermined frequency; a frequency dividing circuit 102 that divides a signal generated by the oscillation circuit 101 to generate a clock signal as a reference for timing; and a control circuit 103 that performs various controls such as a clock operation of the clock signal, control of each electronic circuit element constituting the analog electronic timepiece, and control of changing a drive pulse.

The analog electronic timepiece further includes: a main drive pulse generation circuit 104 that selects and outputs a plurality of types of main drive pulses P1 having different energies in accordance with a main drive pulse control signal from the control circuit 103; and a correction drive pulse generation circuit 105 that outputs a correction drive pulse P2 having an energy larger than that of each main drive pulse P1, in accordance with a correction drive pulse control signal from the control circuit 103.

The analog electronic timepiece further includes a motor drive circuit 107, and the motor drive circuit 107 rotationally drives the stepping motor 108 by the main drive pulse P1 from the main drive pulse generation circuit 104 and the correction drive pulse P2 from the correction drive pulse generation circuit 105.

The analog electronic timepiece further includes: a stepping motor 108 which is rotationally driven by the motor drive circuit 107; and an analog display unit 109 having a time hand for displaying time, a calendar display unit, and the like, which are rotationally driven by the stepping motor 108.

The analog electronic timepiece further includes: a rotation detection circuit 110 that detects an induced signal VRs indicating a rotation state generated by rotation of the stepping motor 108 in a predetermined detection section; and a detection section determination circuit 111 that compares the detection section with the timing at which the rotation detection circuit 110 detects the sense signal VRs exceeding the predetermined reference threshold voltage Vcomp, and determines in which section the sense signal VRs is detected.

As control modes in which the control circuit 103 controls the rotation of the stepping motor 108, two modes, i.e., a 1 st mode and a 2 nd mode, are prepared.

The 1 st mode is as follows: the stepping motor 108 is rotationally driven using the 1-type main drive pulse P1, and the rotation condition is determined using the entire detection section T as one section. The entire detection section T is used as a section in which rotation is determined when the rotation detection circuit 110 detects the sense signal VRs exceeding the predetermined reference threshold voltage Vcomp, and non-rotation is determined when VRs cannot be detected. When the stepping motor 108 is not rotated in the interval, the stepping motor 108 is forcibly rotated by driving with the correction drive pulse P2.

The 2 nd mode is the following mode: the stepping motor 108 is rotationally driven by using a plurality of types of main drive pulses P1, and the rotation state is determined by dividing the detection interval T into a plurality of intervals (3 intervals in the present embodiment). And the 2 nd mode is a mode as follows: when it is detected that the stepping motor 108 is in the critical rotation (in a state where the energy is not enough although the rotation is possible), the main drive pulse P1 is pulse-increased, and the pulse control is performed at an early stage before the rotation is not performed.

In the 2 nd mode, the detection section T is divided into a plurality of sections, the rotation state of the stepping motor 108 is determined based on the generation state of the induction signal VRs in each section (the mode of the induction signal VRs), and a drive pulse corresponding to the rotation state is selected and driven. In the 2 nd mode, the detection section discrimination circuit 111 determines to which section the sense signal VRs exceeding the reference threshold voltage Vcomp detected by the rotation detection circuit 110 belongs. At this time, the control circuit 103 determines the rotation state based on the pattern of the section in which the sense signal VRs exceeding the reference threshold voltage Vcomp is generated, and performs pulse control such as pulse up or pulse down of the main drive pulse P1.

The analog electronic timepiece further includes: a secondary battery 113 as a power source that supplies electric power to each electronic circuit element of an analog electronic timepiece represented by the stepping motor 108; a solar cell 114 that charges the secondary battery 113; and a voltage detection circuit 112 that detects the voltage of the secondary battery 113. The secondary battery 113 functions as a power source that supplies at least electric power to the stepping motor.

Here, the oscillation circuit 101 and the frequency dividing circuit 102 constitute a signal generating means, and the analog display section 109 constitutes a notifying means. The rotation detection circuit 110 and the detection section discrimination circuit 111 constitute rotation detection means. The solar cell 114 constitutes a power generation unit that generates electric power and a charging unit that charges the secondary battery 113. The main drive pulse generating circuit 104 and the correction drive pulse generating circuit 105 constitute a drive pulse generating unit. The oscillation circuit 101, the frequency dividing circuit 102, the control circuit 103, the main drive pulse generating circuit 104, the correction drive pulse generating circuit 105, and the motor drive circuit 107 constitute control means.

The solar cell 114 generates power to charge the secondary battery 113. Electric power is supplied from a secondary battery 113 as a power source to a circuit element of an analog electronic timepiece represented by the stepping motor 108, so that the analog electronic timepiece operates.

To schematically explain a time display operation as a normal operation, in fig. 1, an oscillation circuit 101 generates a signal of a predetermined frequency, and a frequency dividing circuit 102 divides the signal generated by the oscillation circuit 101, generates a clock signal (for example, a signal having a period of 1 second) serving as a reference for timing, and outputs the clock signal to a control circuit 103.

The control circuit 103 performs a timing operation based on the clock signal, and outputs a main drive pulse control signal to the main drive pulse generation circuit 104 at a predetermined cycle so as to rotationally drive the stepping motor 108 with a drive pulse corresponding to the magnitude of the load or the voltage of the secondary battery 113.

In the embodiment of the present invention, a plurality of kinds of drive pulses are prepared as drive pulses for rotationally driving the stepping motor 108. As the drive pulses, a plurality of types (i.e., a plurality of levels) of main drive pulses P1 having different energies from each other and a correction drive pulse P2 having a larger energy than each main drive pulse P1 are used.

The main drive pulse P1 is a drive pulse for rotationally driving the stepping motor 108 when the normal time hand (second hand, minute hand, hour hand) is moving, and the correction drive pulse P2 is a drive pulse for forcibly rotating the stepping motor 108 when the stepping motor 108 cannot be rotated by the main drive pulse P1.

The main drive pulse generating circuit 104 outputs a main drive pulse P1 of an energy level corresponding to the main drive pulse control signal from the control circuit 103 to the motor drive circuit 107. The motor drive circuit 107 rotationally drives the stepping motor 108 by the main drive pulse P1. The stepping motor 108 is rotationally driven by the main drive pulse P1, and rotationally drives the time hand of the analog display unit 109. Thus, when the stepping motor 108 is normally rotated, the current time of the time hand is displayed on the analog display unit 109.

The rotation detection circuit 110 detects a detection signal VRs exceeding a predetermined reference threshold voltage Vcomp among the induction signals VRs generated by the rotational free vibration of the stepping motor 108 in a predetermined detection section T.

The rotation detection circuit 110 sets the reference threshold voltage Vcomp to: the detection signal VRs exceeding the predetermined reference threshold voltage Vcomp is detected when the rotor (not shown) of the stepping motor 108 performs a certain degree of fast operation such as when the stepping motor 108 rotates, and the detection signal VRs does not exceed the reference threshold voltage Vcomp when the rotor does not perform a certain degree of fast operation such as when the stepping motor 108 does not rotate.

When the control mode is the 1 st mode, the detection section discrimination circuit 111 does not perform the section discrimination, and therefore the detection result of the rotation detection circuit 110 is directly input to the control circuit 103.

The control circuit 103 determines that the stepping motor 108 is rotating when the rotation detection circuit 110 detects the induction signal VRs exceeding the reference threshold voltage Vcomp in the detection interval. When the rotation detection circuit 110 does not detect the induced signal VRs exceeding the reference threshold voltage Vcomp during the detection period, the control circuit 103 determines that the stepping motor 108 is not rotating and forcibly drives the stepping motor 108 with the correction drive pulse P2.

When the control mode is the 2 nd mode, the detection section determination circuit 111 compares the detection time and the detection section of the sense signal VRs exceeding the reference threshold voltage Vcomp detected by the rotation detection circuit 110, and determines in which section the sense signal VRs is detected. The control circuit 103 determines the rotation state of the stepping motor 108 based on the pattern of the induced signal VRs determined by the detection section determination circuit 111, and determines the energy margin of the main drive pulse P1 driven at this time.

The control circuit 103 outputs a control signal to the main drive pulse generation circuit 104 in accordance with the pattern of the sense signal VRs to perform pulse control such that the energy of the main drive pulse P1 is increased by 1 step (pulse up) or the energy of the main drive pulse P1 is decreased by 1 step (pulse down), or outputs a control signal to the correction drive pulse generation circuit 105 to perform pulse control such that the correction drive pulse P2 performs driving.

The main drive pulse generation circuit 104 or the correction drive pulse generation circuit 105 outputs a drive pulse corresponding to the control signal to the motor drive circuit 107, and the motor drive circuit 107 rotationally drives the stepping motor 108 by the drive pulse.

Further, the control circuit 103 switches the control mode between the 1 st mode and the 2 nd mode according to the voltage of the secondary battery 113. That is, the control circuit 103 switches between the 1 st mode and the 2 nd mode when the voltage of the secondary battery 113 detected by the voltage detection circuit 112 reaches the current switching voltage as the predetermined voltage. In the present embodiment, the switching voltage is a 1 st reference voltage Lo which is a predetermined low voltage and a 2 nd reference voltage Hi which is higher than the 1 st reference voltage Lo, and is switched according to the rotation state of the stepping motor 108.

Fig. 2 is a timing chart of the embodiment of the present invention, which is a timing chart when the stepping motor 108 is driven by the main drive pulse P1 in the 2 nd mode. Fig. 2 shows the remaining energy of the drive pulse, and the pattern and pulse control operation of the sense signal VRs indicating the rotational position and the rotational state of the rotor 202 of the stepping motor 108.

In fig. 2, P1 indicates the main drive pulse P1, and indicates a region in which the rotor 202 of the stepping motor 108 is rotationally driven by the main drive pulse P1, and a to e indicate regions in which the rotational position of the rotor 202 is determined by free vibration after the stop of the driving of the main drive pulse P1.

A predetermined time immediately after the driving of the main drive pulse P1 is set as a 1 st section T1, a predetermined time following the 1 st section T1 is set as a 2 nd section T2, and a predetermined time following the 2 nd section is set as a 3 rd section T3. In this way, the entire detection section T started immediately after the driving of the main drive pulse P1 is divided into a plurality of sections (3 sections T1 to T3 in the present embodiment). In the embodiment of the present invention, the period during which the sense signal VRs is not detected, that is, the mask section is not provided.

When the XY coordinate space in which the main magnetic pole (a straight arrow in the drawing showing the rotational operation of fig. 2) of the rotor 202 is located is divided into the 1 st to 4 th quadrants I to IV by the rotation of the rotor 202 around the rotor 202, the 1 st to 3 rd sections T1 to T3 can be expressed as follows.

That is, in the normal driving state (i.e., the rotation state in which the margin of driving energy is large), the 1 st segment T1 is a segment in which the forward (counterclockwise) rotation state of the rotor 202 is determined in the 3 rd quadrant III of the space around the rotor 202, the 2 nd segment T2 is a segment in which the first forward rotation state and the first reverse (clockwise) rotation state of the rotor 202 are determined in the 3 rd quadrant III, and the 3 rd segment T3 is a segment in which the rotation state after the first reverse rotation of the rotor 202 is determined in the 3 rd quadrant III. Here, the normal drive refers to a state in which a normally driven load can be normally driven by the main drive pulse P1, and in the present embodiment, a state in which the time hand is used as a load and the normal drive can be normally driven by the main drive pulse P1 is referred to as the normal drive.

In a state where the drive energy is slightly smaller than the normal drive (a drive state where the load increment is small, a rotation state where the margin of energy is small), the 1 st section T1 is a section for determining the forward rotation state of the rotor 202 in the 2 nd quadrant II, the 2 nd section T2 is a section for determining the first forward rotation state and the first reverse rotation state of the rotor 202 in the 3 rd quadrant III, and the 3 rd section T3 is a section for determining the rotation state after the first reverse rotation of the rotor 202 in the 3 rd quadrant III.

In a state where the energy of the rotation state in which the driving energy is smaller than the margin (the driving state in which the load increment is large, the rotation state in which the energy reaches the limit), the 1 st section T1 is a section for determining the forward rotation state of the rotor 202 in the 2 nd quadrant II, the 2 nd section T2 is a section for determining the forward rotation state of the rotor 202 in the 2 nd quadrant II and the first forward rotation state of the rotor 202 in the 3 rd quadrant III, and the 3 rd section T3 is a section for determining the rotation state after the first reverse rotation of the rotor 202 in the 3 rd quadrant III.

In a state where the drive energy is smaller than the energy in the critical rotation state (a drive state where the load increment is extremely large, a non-rotation state where the energy is insufficient), the rotor 202 cannot be rotated.

For example, in fig. 2, in the stepping motor control circuit of the present embodiment, in the normal driving state, the sense signal VRs generated in the region b is detected in the 1 st segment T1 and the 2 nd segment T2, the sense signal VRs generated in the region c is detected in the 2 nd segment T2, and the sense signal VRs generated after the region c is detected in the 3 rd segment T3.

When the rotation detection circuit 110 detects the sense signal VRs exceeding the reference threshold voltage Vcomp as the determination value "1" and the rotation detection circuit 110 fails to detect the sense signal VRs exceeding the reference threshold voltage Vcomp as the determination value "0", in the example of the normal driving of fig. 2, (0, 1, 0) is obtained as a pattern indicating the rotation state (the determination value of the 1 st section, the determination value of the 2 nd section, and the determination value of the 3 rd section). At this time, the control circuit 103 determines that the margin of the drive energy is large, and performs pulse control so that the drive energy is decreased by 1 step (pulse down) and changed to the main drive pulse P1 decreased by 1 step.

Fig. 3 is a determination diagram summarizing the pulse control operation according to the present embodiment. In fig. 3, as described above, the determination value "1" indicates a case where the sensing signal VRs exceeding the reference threshold voltage Vcomp is detected, and the determination value "0" indicates a case where the sensing signal VRs exceeding the reference threshold voltage Vcomp cannot be detected. "1/0" indicates that the determination value may be "1" or "0".

As shown in fig. 3, the rotation detection circuit 110 detects whether or not there is an induced signal VRs exceeding the reference threshold voltage Vcomp, and the detection section determination circuit 111 determines the pattern of the induced signal VRs in which section the induced signal VRs belongs. The control circuit 103 refers to the determination map of fig. 3 stored in the control circuit 103 in accordance with the pattern of the sense signal VRs, and performs pulse control described later, such as pulse up or pulse down of the main drive pulse P1 or drive of the correction drive pulse P2, to control the rotation of the stepping motor 108.

For example, when the mode is (1/0, 0, 0), the control circuit 103 determines that the stepping motor 108 is not rotating (non-rotating), controls the correction drive pulse generation circuit 105 to drive the stepping motor 108 with the correction drive pulse P2, and then controls the main drive pulse generation circuit 104 to perform driving with the main drive pulse P1 shifted to the higher level by 1 at the next driving.

When the mode is (1/0, 0, 1), the control circuit 103 determines that the stepping motor 108 is rotating but the drive energy for the load is very low, that is, determines that the next drive is possible to be in the non-rotating state, and the control circuit 103 does not drive the correction drive pulse P2 but controls the main drive pulse generation circuit 104 so that the next drive is performed with the main drive pulse P1 that is higher by 1.

When the mode is (1, 1, 1/0), the control circuit 103 determines that the stepping motor 108 has rotated and the remaining amount of drive energy for the load is small, but the next rotation is still possible, and the control circuit 103 controls the main drive pulse generating circuit 104 so that the next drive is performed without changing the main drive pulse P1.

When the mode is (0, 1, 1/0), the control circuit 103 determines that the stepping motor 108 is rotating and the drive energy for the load is too large, and the control circuit 103 controls the main drive pulse generation circuit 104 to change the main drive pulse P1 to the main drive pulse P1 that is lowered by 1 step.

Fig. 4 is a flowchart showing the operation of the stepping motor control circuit and the analog electronic timepiece according to embodiment 1 of the present invention, and is a flowchart mainly showing the processing of the control circuit 103.

Next, the operation of embodiment 1 of the present invention will be described in detail with reference to fig. 1 to 4. In the initial state, the switching voltage is set to the 1 st reference voltage Lo at a low level.

The control circuit 103 resets the rank N of the main drive pulse P1 to 0 (main drive pulse P10) which is the lowest energy, and resets the value of the number N of consecutive drives to 0 (step S501).

Next, the control circuit 103 causes the voltage detection circuit 112 to detect the voltage of the secondary battery 113, and determines whether or not the voltage detection circuit 112 detects the switching voltage (here, the 1 st reference voltage Lo), that is, whether or not the voltage of the secondary battery 113 falls below the switching voltage (step S601).

When the control circuit 103 determines in step S601 that the voltage of the secondary battery 113 exceeds the switching voltage, that is, does not decrease to the switching voltage, the control circuit drives in the 1 st mode.

In the 1 st mode, the control circuit 103 outputs a control signal to the main drive pulse generating circuit 104 to fix the main drive pulse P1 to the main drive pulse P1m of the maximum energy level among the plurality of kinds of main drive pulses P1 used in the 2 nd mode to drive the stepping motor 108 (step S602). The main drive pulse generating circuit 104 fixes the main drive pulse P1 to the main drive pulse P1m of 1 maximum energy in response to the control signal from the control circuit 103, and drives the stepping motor 108 via the motor drive circuit 107.

Thus, since the main drive pulse P1 driven in the 1 st mode is the 1 st type main drive pulse P1, the pulse rise does not occur at an early stage even when the energy is reduced, and the main drive pulse is used for driving as long as the driving is possible. Therefore, unnecessary energy waste can be prevented.

Further, since the main drive pulse P1 driven in the 1 st mode is the main drive pulse P1m of 1 maximum energy out of the main drive pulses P1 used in the 2 nd mode, the stepping motor 108 can be reliably rotated even in the case where the voltage of the secondary battery 113 is reduced.

The rotation detection circuit 110 is configured to: in the detection section T immediately after the driving of the stepping motor 108, the induced signal VRs exceeding the reference threshold voltage Vcomp is detected when the stepping motor 108 rotates, and the induced signal VRs exceeding the reference threshold voltage Vcomp is not detected when the stepping motor 108 does not rotate.

The control circuit 110 determines whether or not the stepping motor 108 has rotated based on the detection result of the rotation detection circuit 110 (step S603), and if it is determined that the stepping motor has rotated, the process returns to step S601.

When it is determined in the processing step S603 that the stepping motor 108 is not rotating, the control circuit 103 outputs a control signal to the correction drive pulse generation circuit 105 to drive the stepping motor with the correction drive pulse P2 (step S604). The correction drive pulse generating circuit 105 drives the stepping motor 108 with the correction drive pulse P2 via the motor drive circuit 107 in response to the control signal from the control circuit 103.

Next, the control circuit 103 switches the switching voltage to the 2 nd reference voltage Hi higher than the 1 st reference voltage Lo (step S605). Thereby, the level of the switching voltage becomes high, and therefore in the subsequent processing step S601, a case where the secondary battery 113 is lowered to the switching voltage is detected in advance and shifted to the 2 nd mode, thereby avoiding the driving of the correction driving pulse P2 in the processing step S604. This can suppress energy consumption.

On the other hand, when it is determined in step S601 that the voltage of the secondary battery 113 has dropped to the switching voltage or less, the control circuit 103 drives in the 2 nd mode.

In the 2 nd mode, the control circuit 103 outputs a control signal to the main drive pulse generating circuit 104 to select the main drive pulse P1n of the energy level n at this time ("0" of the lowest energy level here) (step S502), and drives the stepping motor 108 with the main drive pulse P1 n.

The main drive pulse generating circuit 104 outputs a main drive pulse P1n having an energy corresponding to the control signal to the motor drive circuit 107, and the motor drive circuit 107 rotationally drives the stepping motor 108 by the main drive pulse P1 n.

The rotation detection circuit 110 detects the induced signal VRs exceeding the reference threshold voltage Vcomp among the induced signals VRs generated by the rotation of the stepping motor 108 in the detection section T. The detection section determination circuit 111 determines to which section T1 to T3 the sense signal VRs exceeding the reference threshold voltage Vcomp belongs.

The control circuit 103 determines whether or not the detection section determination circuit 111 determines that the detection time T of the sense signal VRs is within the section T1 (i.e., whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected within the 1 st section T1) (step S504).

If the control circuit 103 determines in step S504 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the segment T1 (the pattern is (0, x, x) — where the determination value "x" is independent of whether the determination value is "1" or "0"), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the segment T2 in the same manner as described above (step S505).

When the control circuit 103 determines in step S505 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T2 (when the pattern is (0, 0, x)), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T3 in the same manner as described above (step S506).

If the control circuit 103 determines in step S506 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T3 (the pattern is (x, 0, 0), or the pattern is not rotated in fig. 3), the control circuit increases the main drive pulse P1 by 1 step to change to the main drive pulse P1 (n + 1) when the level n of the main drive pulse P1 is not the maximum level m after driving the stepping motor 108 with the correction drive pulse P2 having the same polarity as the main drive pulse P1 in step S503 (step S507), and then returns to step S601, and drives the next driving with the main drive pulse P1 (n + 1) (steps S508 and S510).

When the rank n of the main drive pulse P1 is the maximum rank m in step S508, the control circuit 103 changes the main drive pulse P1 to the main drive pulse P1 (n-a) having a predetermined energy reduction amount, returns to step S601, and drives the next time by the main drive pulse P1 (n-a) (step S509). At this time, since the rotation is not enabled even by the drive pulse P1m of the maximum energy level m out of the main drive pulses P1, the energy waste when driving by the main drive pulse P1m of the maximum energy level m at the time of the next driving can be reduced. At this time, the main drive pulse P10 may be changed to the minimum energy in order to obtain a large power saving effect.

When the control circuit 103 determines in the processing step S506 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T3 (when the pattern is (x, 0, 1)). and the rank n of the main drive pulse P1 is not the maximum rank m, the control circuit increases the main drive pulse P1 by 1 rank to change it to the main drive pulse P1 (n + 1), and returns to the processing step S601, and drives the next time by the main drive pulse P1 (steps S511 and S510; when the load increment in fig. 3 is large).

If the rank n of the main drive pulse P1 is the maximum rank m in step S511, the control circuit 103 returns to step S601 without changing the main drive pulse P1, and drives the next time by the main drive pulse P1 (step S513).

When the control circuit 103 determines in the processing step S504 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the segment T1 (when the pattern is (1, x, x)), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the segment T2 in the same manner as described above (step S512).

If the control circuit 103 determines in the processing step S512 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T2 (if the pattern is (1, 0, x)), the process proceeds to the processing step S506 and the above-described processing is performed.

If the control circuit 103 determines in the processing step S512 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T2 (if the pattern is (1, 1, x)), the process proceeds to a processing step S513.

If the control circuit 103 determines in step S505 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T2 (if the pattern is (0, 1, x)), the control circuit maintains the rank without changing the rank because the rank cannot be lowered when the rank n of the main drive pulse P1 is the lowest rank 0, and returns to step S601 (steps S514 and S518).

If it is determined in step S514 that the rank N of the main drive pulse P1 is not the lowest rank 0, the control circuit 103 adds 1 to the number N of consecutive generations (step S515), determines whether the number N has reached a predetermined number (160 in the present embodiment) (step S516), returns to step S601 without changing the rank of the main drive pulse P1 if the predetermined number has not been reached (step S518), lowers the rank of the main drive pulse P1 by 1 if the predetermined number has been reached, and returns to step S601 by resetting the number N of consecutive generations to 0 (step S517).

Thus, when the secondary battery 113 is lowered to the switching voltage or less, the 2 nd mode drive control is performed in which the pulse rise is performed when the energy of the main drive pulse P1 reaches the limit drive, and reliable rotation drive is performed.

While the operation of the above-described mode 2 is being repeated, the secondary battery 113 is charged by the solar cell 114, and when the switching voltage is exceeded, the determination in step S601 is no, and the mode is shifted to the mode 1.

As described above, the stepping motor control circuit according to embodiment 1 of the present invention includes: a secondary battery 113 as a power source that supplies at least the stepping motor 108 with electric power; a voltage detection circuit 112 that detects the voltage of the secondary battery 113; a rotation detection unit that detects a rotation condition of the stepping motor 108; and a control unit that drives the stepping motor 108 in a 1 st mode or a 2 nd mode, wherein in the 1 st mode, a driving pulse corresponding to a rotation condition of the stepping motor 108 is selected from the 1 st main driving pulse P1 and a correction driving pulse P2 having an energy larger than that of the 1 st main driving pulse P1 to drive the stepping motor 108, in the 2 nd mode, a driving pulse corresponding to the rotation condition of the stepping motor 108 is selected from the plural kinds of main driving pulses P1 and a correction driving pulse P2 having an energy larger than that of the plural kinds of main driving pulses P1 to drive the stepping motor 108, and the control unit switches to one of the 1 st mode and the 2 nd mode to drive the stepping motor depending on whether or not the voltage of the secondary battery 113 detected by the voltage detection circuit 112 exceeds a predetermined switching voltage.

Therefore, since the driving is performed in the 1 st mode in which the driving is performed by the 1 st main drive pulse P1 before the voltage of the secondary battery 113 decreases to the switching voltage or less, unnecessary pulse rise of the main drive pulse can be prevented, and energy consumption can be suppressed. Further, since the stepping motor 108 can be driven by a main drive pulse according to the rotation state thereof, the rotation can be prevented from occurring.

Further, an analog electronic timepiece according to embodiment 1 of the present invention includes: a stepping motor 108 that rotationally drives the time hand; and a stepping motor control circuit for controlling the stepping motor 108, wherein the stepping motor control circuit is configured by the stepping motor control circuit, and therefore, by driving with the main drive pulse P1 corresponding to the voltage of the secondary battery 113 and the rotation state of the stepping motor 108, the occurrence of non-rotation can be prevented, and energy consumption can be suppressed, and thus, an effect such as accurate needle movement can be achieved.

Fig. 5 is a flowchart showing the operation of the stepping motor control circuit and the analog electronic timepiece according to embodiment 2 of the present invention, and the same reference numerals are given to the parts that perform the same processing as in fig. 4. The block diagram and the pulse control operation of embodiment 2 are the same as those of fig. 1 to 3.

In embodiment 2 as well, the same thing applies to switching the control mode depending on whether or not the secondary battery 113 exceeds the switching voltage, as in embodiment 1.

However, while the above-described embodiment 1 is configured to operate in the 1 st mode when the secondary battery 113 exceeds the switching voltage and to operate in the 2 nd mode when the secondary battery 113 falls below the switching voltage, the embodiment 2 is different in that: the operation is performed in the 2 nd mode when the secondary battery 113 exceeds the switching voltage, and the operation is performed in the 1 st mode when the secondary battery 113 falls below the switching voltage.

That is, when the control circuit 103 determines in step S601 of fig. 5 that the voltage of the secondary battery 113 exceeds the switching voltage (the 1 st reference voltage Lo in the initial setting), that is, does not decrease to the switching voltage, it drives in the 2 nd mode. In the 2 nd mode, the processing described below in the processing step S502 is performed. On the other hand, when it is determined in step S601 that the voltage of the secondary battery 113 has dropped to the switching voltage or less, the control circuit 103 drives in the 1 st mode. The processing described below in processing step S602 is performed in mode 1.

In the stepping motor control circuit according to embodiment 2 as well, the control circuit 103 switches the control mode between the 1 st mode and the 2 nd mode to drive the stepping motor 108, depending on whether or not the voltage of the secondary battery 113 detected by the voltage detection circuit 112 exceeds a predetermined switching voltage, as in embodiment 1.

Therefore, after the voltage of the secondary battery 113 decreases to the switching voltage or less, the driving is performed in the 1 st mode in which the driving is performed by the 1 st main driving pulse P1, and therefore, unnecessary pulse rise of the main driving pulse P1 can be prevented, and energy consumption can be suppressed.

Further, since the secondary battery 113 is driven in the 2 nd mode in which it is driven by the plurality of types of main drive pulses P1 before the voltage thereof decreases to the switching voltage or less, it is possible to drive the secondary battery by the main drive pulse P1 corresponding to the rotation state of the stepping motor 108, and it is possible to prevent the occurrence of the non-rotation.

Further, an analog electronic timepiece according to embodiment 2 includes: a stepping motor 108 that rotationally drives the time hand; and a stepping motor control circuit for controlling the stepping motor 108, wherein the stepping motor control circuit is configured by the stepping motor control circuit, and therefore, by driving with the main drive pulse P1 corresponding to the voltage of the secondary battery 113 and the rotation state of the stepping motor 108, the occurrence of non-rotation can be prevented, and energy consumption can be suppressed, and thus, an effect such as accurate needle movement can be achieved.

Next, embodiment 3 of the present invention will be described. The block diagram of embodiment 3 is the same as that of fig. 1.

In the above-described embodiments 1 and 2, two modes are provided, that is, the 1 st mode in which the driving is performed using the 1 st type of main drive pulse P1 and the correction drive pulse P2 having an energy larger than that of the main drive pulse, and the 2 nd mode in which the driving is performed using the plural types of main drive pulses P1 having energies different from each other and the correction drive pulse P2 having an energy larger than that of each main drive pulse P1, but the 3 rd mode is provided.

Further, while the above-described embodiment 1 is configured to perform the operation in the 2 nd mode when the voltage of the secondary battery 113 decreases to a predetermined voltage, and to perform the operation in the 1 st mode when the voltage of the secondary battery 113 exceeds the predetermined voltage, the above-described embodiment 3 is configured to: the operation in the 2 nd mode is performed when the voltage of the secondary battery 113 decreases to the predetermined voltage, the operation in the 1 st mode is performed when the voltage of the secondary battery 113 exceeds the predetermined voltage, and the operation in the 3 rd mode is performed after the rotation state of the stepping motor 108 changes to the predetermined state in the operation in the 1 st mode. Further, the configuration is: in the operation in the 3 rd mode, when the voltage of the secondary battery 113 decreases to the predetermined voltage, the mode shifts to the 2 nd mode.

In the 2 nd mode, which is a mode when the voltage of the secondary battery 113 is a predetermined value or less, as described above, the stepping motor 108 is driven using a plurality of types of main drive pulses (the 1 st main drive pulse group) having mutually different energies and the correction drive pulse P2 having an energy larger than that of the 1 st main drive pulse group, and the rotation condition is detected using the 1 st detection section divided into 3 sections.

On the other hand, in the 1 st mode, which is a mode when the voltage of the secondary battery 113 exceeds a predetermined value, the driving is performed using the 1 st main driving pulse P1 and the correction driving pulse P2 having an energy larger than that of the main driving pulse P1, and the rotation condition is detected using the 2 nd detection section divided into 4 sections. The time widths of the 1 st detection section and the 2 nd detection section are the same.

When the rotation state of the stepping motor 108 is a predetermined state during the driving in the 1 st mode, the driving is switched from the 1 st mode to the 3 rd mode, and in the 3 rd mode, the driving is performed using a plurality of types of main drive pulses P1 (the 2 nd main drive pulse group) having energy smaller than that of the 1 st main drive pulse group and different from each other, and a correction drive pulse P2 having energy larger than that of each main drive pulse P1. The 3 rd mode is a mode when the voltage of the secondary battery 113 exceeds a predetermined value, and the rotation condition is detected using the 2 nd detection section divided into 4 sections in the same manner as the 1 st mode.

In addition, although drive pulses of various energies can be used as the main drive pulse P1 used in the 1 st mode, in embodiment 3, the main drive pulse P1 used in the 1 st mode uses a main drive pulse of the maximum energy in the 2 nd main drive pulse group. When it is determined in the 1 st mode that the drive energy is large and the pulse drop is necessary, the mode is switched to the 3 rd mode in which the 2 nd main drive pulse group is used for driving.

Fig. 6 is a timing chart of embodiment 3, showing a timing chart when the stepping motor 108 is driven by the main drive pulse P1 in the 3 rd mode.

In the 3 rd mode, the detection section T immediately after the driving of the main drive pulse P1 is divided into a 4 th section T11, a 5 th section TS following a predetermined time after the 4 th section T11, a 6 th section T21 following a predetermined time after the 5 th section TS, and a 7 th section T3 following a predetermined time after the 6 th section T21.

The 4 th section T11 and the 7 th section T3 correspond to the 1 st section and the 3 rd section T3 of fig. 2, respectively. In embodiment 3, the 2 nd section T2 in fig. 2 is divided (e.g., equally divided) into the 5 th section TS and the 6 th section T21. The 5 th section TS corresponds to the front section of the 2 nd section T2, and the 6 th section T21 corresponds to the rear section of the 2 nd section T2. When the state changes from the state in which the sense signal VRs exceeding the reference threshold voltage Vcomp is generated in the 6 th segment T21 to the state in which the margin is generated in the driving energy, the sense signal VRs is generated in advance, and therefore the sense signal VRs is generated not in the 6 th segment T21 but in the 5 th segment TS. This makes it possible to determine a change in the remaining amount of energy.

In fig. 6, the sections (1 st section T1 to 3 rd section T3) of the detection section T in the 2 nd pattern are also described.

In this way, the entire detection section T started immediately after the driving of the main drive pulse P1 is divided into a plurality of sections (4 sections T4 to T7 in the present embodiment).

In embodiment 3, the method of dividing the detection section T in the 1 st mode is the same as that in the 3 rd mode.

When the XY coordinate space in which the main magnetic pole (a linear arrow in the figure showing the rotational operation of fig. 6) of the rotor 202 is located is divided into the 1 st quadrant I to the 4 th quadrant IV according to the rotation of the rotor 202 around the rotor 202 of the stepping motor 108, the 4 th interval T11 to the 7 th interval T3 can be expressed as follows.

That is, in the normal driving state (i.e., the rotation state in which the margin of driving energy is large), the 4 th section T11 is a section for determining the forward (counterclockwise) rotation state of the rotor 202 in the 3 rd quadrant III of the space around the rotor 202, the 5 th section TS is a section for determining the first forward rotation state and the first reverse (clockwise) rotation state of the rotor 202 in the 3 rd quadrant III, the 6 th section T21 is a section for determining the first reverse rotation state of the rotor 202 in the 3 rd quadrant III, and the 7 th section T3 is a section for determining the rotation state after the first reverse rotation of the rotor 202. Here, the normal drive refers to a state in which a normally driven load can be normally driven by the main drive pulse P1, and in the present embodiment, a state in which the time hand is used as a load and the normal drive can be normally driven by the main drive pulse P1 is referred to as the normal drive.

In a state where the drive energy is slightly smaller than the normal drive (a drive state where the load increment is small and a rotation state where the margin of energy is small), the 4 th section T11 is a section for determining the forward rotation state of the rotor 202 in the 2 nd quadrant II, the 5 th section TS is a section for determining the first forward rotation state of the rotor 202 in the 3 rd quadrant III, the 6 th section T21 is a section for determining the first forward rotation state and the first reverse rotation state of the rotor 202 in the 3 rd quadrant III, and the 7 th section T3 is a section for determining the rotation state after the first reverse rotation of the rotor 202 in the 3 rd quadrant III.

In a state where the energy of the rotation state in which the driving energy is smaller than the margin (the driving state in which the load increment is large, the rotation state in which the energy reaches the limit), the 4 th section T11 is a section for determining the forward rotation state of the rotor 202 in the 2 nd quadrant II, the 5 th section TS is a section for determining the forward rotation state of the rotor 202 in the 2 nd quadrant II, the 6 th section T21 is a section for determining the forward rotation state of the rotor 202 in the 3 rd quadrant III, and the 7 th section T3 is a section for determining the rotation state after the first reverse rotation of the rotor 202 in the 3 rd quadrant III.

In a state where the drive energy is smaller than the energy in the critical rotation state (a drive state where the load increase is large, a non-rotation state where the energy is insufficient), the rotor 202 cannot be rotated.

In a state where energy is larger than that in the normal drive (a high-energy drive state, a state where the margin of energy is extremely large), the 4 th section T11 is a section for determining the first forward rotation state of the rotor 202 in the 3 rd quadrant III, the 5 th section TS is a section for determining the first reverse rotation state of the rotor 202 in the 3 rd quadrant III, the 6 th section T21 is a section for determining the first reverse rotation state of the rotor 202 in the 3 rd quadrant III, and the 7 th section T3 is a section for determining the rotation state after the first reverse rotation of the rotor 202 in the 3 rd quadrant III.

For example, in fig. 6, in the stepping motor control circuit of the present embodiment, in the normal driving state, the sense signal VRs generated in the detection region b in the 4 th section T11 and the 5 th section TS, the sense signal VRs generated in the detection region c in the 5 th section TS and the 6 th section T21, and the sense signal VRs generated after the detection region c in the 7 th section T3 are detected.

When the rotation detection circuit 110 detects the sense signal VRs exceeding the reference threshold voltage Vcomp as the determination value "1" and the rotation detection circuit 110 fails to detect the sense signal VRs exceeding the reference threshold voltage Vcomp as the determination value "0", in the example of the normal driving of fig. 6, (0, 0, 1, 0) is obtained as a pattern indicating the rotation state (the determination value in the 4 th section, the determination value in the 5 th section, the determination value in the 6 th section, and the determination value in the 7 th section). At this time, the control circuit 103 determines that the margin of the drive energy is large, and performs pulse control so that the drive energy is maintained without change.

Fig. 7 is a decision diagram summarizing the pulse control operation according to embodiment 3. In fig. 7, as described above, the determination value "1" indicates a case where the sensing signal VRs exceeding the reference threshold voltage Vcomp is detected, and the determination value "0" indicates a case where the sensing signal VRs exceeding the reference threshold voltage Vcomp cannot be detected. "1/0" indicates that the determination value may be "1" or "0".

As shown in fig. 7, the rotation detection circuit 110 detects whether or not there is an induced signal VRs exceeding the reference threshold voltage Vcomp, and the detection section determination circuit 111 determines the pattern of the induced signal VRs in which section the induced signal VRs belongs. In the 1 st mode and the 3 rd mode, the control circuit 103 refers to the determination map of fig. 7 stored in the control circuit 103 in accordance with the pattern of the sense signal VRs, and performs a pulse control operation to be described later, such as pulse up or pulse down of the main drive pulse P1 or drive of the correction drive pulse P2, to control the drive of the stepping motor 108.

In the 2 nd mode, the detection section T is divided into 3 sections of the 1 st section T1 to T3, and pulse control is performed using the determination map of fig. 3.

Fig. 8 is a flowchart showing the operation of the stepping motor control circuit and the analog electronic timepiece according to embodiment 3 of the present invention, and is a flowchart mainly showing the processing of the control circuit 103.

Next, the operation of embodiment 3 of the present invention, which is different from that of embodiment 1, will be described with reference to fig. 1 and 6 to 8.

The control circuit 103 resets the rank N of the main drive pulse P1 to 0 (e.g., the main drive pulse P10 of the lowest energy in the 1 st main drive pulse group), resets the value of the number N of consecutive drives to 0, and sets the main drive pulse P1 to the main drive pulse P1m (step S501).

Next, the control circuit 103 causes the voltage detection circuit 112 to detect the voltage of the secondary battery 113, and determines whether or not the voltage detection circuit 112 detects the switching voltage (here, the 1 st reference voltage Lo that is initially set), that is, whether or not the voltage of the secondary battery 113 falls below the switching voltage (step S601).

When it is determined in step S601 that the voltage of the secondary battery 113 has decreased to the switching voltage, the control circuit 103 performs the mode 2 driving. In the 2 nd pattern, similarly to the description with respect to fig. 4, the processing of the processing steps S502 to S518 is repeatedly executed similarly to the 1 st embodiment, using the 1 st detection section, the 1 st main drive pulse group, and the correction drive pulse P2 divided into 3 sections.

On the other hand, when the control circuit 103 determines in step S601 that the voltage detection circuit 112 has not detected the switching voltage, that is, the voltage of the secondary battery 113 exceeds the switching voltage, the operation shifts to the 1 st mode and the 3 rd mode as described below. In the 1 st and 3 rd modes, an operation is performed using the 2 nd main drive pulse group and the 2 nd detection section divided into 4 sections.

When it is determined in step S601 that the voltage of the secondary battery 113 exceeds the switching voltage, the control circuit 103 determines whether or not the main drive pulse P1 is the main drive pulse P1m having the maximum energy among the 2 nd main drive pulse group (step S801).

When the control circuit 103 determines in the processing step S801 that the main drive pulse P1 is the main drive pulse P1m, it outputs a control signal to the main drive pulse generation circuit 104 to drive the stepping motor 108 with the main drive pulse P1m (step S802).

The main drive pulse generation circuit 104 outputs a main drive pulse P1m having an energy corresponding to the control signal to the motor drive circuit 107, and the motor drive circuit 107 rotationally drives the stepping motor 108 by the main drive pulse P1 m.

The rotation detection circuit 110 detects the induced signal VRs exceeding the reference threshold voltage Vcomp among the induced signals VRs generated by the rotation of the stepping motor 108 in the detection section T. The detection section determination circuit 111 determines to which section T11 to T3 the sense signal VRs exceeding the reference threshold voltage Vcomp belongs.

The control circuit 103 causes the detection section determination circuit 111 to determine whether or not the detection time T of the sense signal VRs is within the 4 th section T11 (i.e., whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected within the 4 th section T11) (step S803).

If it is determined in step S803 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T11 (if the pattern is (0, x, x, x)), the control circuit 103 determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the 5 th section TS (step S804).

If it is determined in step S804 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section TS (if the pattern is (0, 0, x, x)), the control circuit 103 determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the 6 th section T21 (step S805).

If it is determined in step S805 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the segment T21 (if the pattern is (0, 0, 0, x)), the control circuit 103 determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the segment T3 (step S806).

When the control circuit 103 determines in step S806 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T3 (when the pattern is (0, 0, 0, 0)), it determines that the stepping motor 108 is not rotating, outputs a control signal to the correction drive pulse generation circuit 105 to drive the correction drive pulse P2 (step S807), and returns to step S601.

The correction drive pulse generating circuit 105 outputs the correction drive pulse P2 to the motor drive circuit 107 in response to the control signal, and the motor drive circuit 107 forcibly rotationally drives the stepping motor 108 with the correction drive pulse P2.

On the other hand, if the control circuit 103 determines in the processing step S806 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T3 (the mode is (0, 0, 0, 1)), and if the control circuit determines in the processing step S805 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T21 (the mode is (0, 0, 1, x)), the process returns to the processing step S601 as it is.

If it is determined in step S804 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section TS (if the pattern is (0, 1, x, x)), the control circuit 103 changes the main drive pulse P1m of the maximum energy level to the main drive pulse P1 (m-1) by 1 step (step S823), and then returns to step S601.

When the control circuit 103 determines in the processing step S803 that the sensing signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T11 (when the pattern is (1, x, x, x)), and when it is determined that the sensing signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section TS (when the pattern is (1, 0, x, x)), the control circuit proceeds to the processing step S805, and when it is determined that the sensing signal VRs exceeding the reference threshold voltage Vcomp is detected in the section TS (when the pattern is (1, 1, x, x)), the control circuit proceeds to the processing step S823, lowers the energy level of the main drive pulse P1m by 1 level, and then returns to the processing step S601.

With the above-described processing, in a state where the voltage of the secondary battery 113 exceeds the switching voltage and the 5 th section TS is "0", the driving of the 1 st mode using the 2 nd detection section, the main drive pulse P1m, and the correction drive pulse P2 is continued.

On the other hand, when the 5 th section TS is "1" in the processing step S804 or the processing step S808 and the main drive pulse P1m is changed to the main drive pulse P1 (m-1) reduced by 1 step in the processing step S823, the control circuit 103 shifts from the processing step S801 to the 3 rd mode to drive in a state where the voltage of the secondary battery 113 still exceeds the switching voltage (step S601).

That is, when the 5 th section TS is "1" in the processing step S804 or the processing step S808 and the voltage of the secondary battery 113 exceeds the switching voltage, the control circuit 103 determines in the processing step S801 that the main drive pulse P1 is not the main drive pulse P1m, and outputs a control signal to the main drive pulse generation circuit 104 so as to drive the stepping motor 108 with the main drive pulse P1 at that time (here, the main drive pulse P1 (m-1)).

The main drive pulse generating circuit 104 outputs a main drive pulse P1 having an energy corresponding to the control signal to the motor drive circuit 107, and the motor drive circuit 107 rotationally drives the stepping motor 108 by the main drive pulse P1.

The control circuit 103 determines whether or not the detection section determination circuit 111 determines that the detection time T of the sense signal VRs is within the 4 th section T11 (i.e., determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected within the 4 th section T11) (step S809).

If the control circuit 103 determines in step S809 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T11 (in the case of the pattern (0, x, x, x)), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section TS in the same manner as described above (step S810).

If the control circuit 103 determines in step S810 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section TS (if the pattern is (0, 0, x, x)), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T21 in the same manner as described above (step S811).

If the control circuit 103 determines in step S811 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the segment T21 (in the case of the pattern of (x, 0, 0, x)), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the segment T3 in the same manner as described above (step S812).

If it is determined in step S812 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected in the section T3 (the pattern is (x, 0, 0, 0), or the non-rotation state in fig. 7), the control circuit 103 increases the main drive pulse P1 by 1 step to change the main drive pulse P1 after driving the stepping motor 108 with the correction drive pulse P2 (step S813), and if the level n of the main drive pulse P1 is not the maximum level m, and then returns to step S601, and drives the next driving with the main drive pulse P1 (steps S814 and S816).

When the level n of the main drive pulse P1 is the maximum level m in step S814, the control circuit 103 changes the main drive pulse P1 to the main drive pulse P1 (n-a) having a predetermined energy reduction amount and returns to step S601, and drives the next time by the main drive pulse P1 (n-a) (step S815). At this time, since the rotation is not enabled even by the drive pulse P1m having the maximum energy level m among the main drive pulses P1, the energy waste can be reduced when the next drive is performed by the main drive pulse P1m having the maximum energy level m. At this time, the main drive pulse P1 with the minimum energy in the 2 nd main drive pulse group may be changed to obtain a large power saving effect.

In the processing step S812, the control circuit 103 determines that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T3 (in the case where the pattern is (x, 0, 0, 1; in the case where the load increment is large in fig. 7)) and the rank n of the main drive pulse P1 is not the maximum rank m, raises the main drive pulse P1 by 1 rank, changes the main drive pulse P1 (n + 1), returns to the processing step S601, and performs the driving by the main drive pulse P1 in the next driving (steps S817 and S816).

When the level n of the main drive pulse P1 is the maximum level m in the processing step S817, the control circuit 103 returns to the processing step S601 without changing the main drive pulse P1, and performs driving by the main drive pulse P1 in the next driving (step S819).

If the control circuit 103 determines in the processing step S811 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T21 (if the pattern is (x, 0, 1, x)), the process proceeds to a processing step S819.

If the control circuit 103 determines in the processing step S810 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected within the section TS (if the pattern is (0, 1, x, x)), the process proceeds to a processing step S820.

When the control circuit 103 determines in step S809 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section T11 (when the pattern is (1, x, x, x)), it determines whether or not the sense signal VRs exceeding the reference threshold voltage Vcomp is detected in the section TS in the same manner as described above (step S818).

If the control circuit 103 determines in the processing step S818 that the sense signal VRs exceeding the reference threshold voltage Vcomp is not detected within the section TS (if the pattern is (1, 0, x, x)), the process proceeds to the processing step S811 to perform the above-described processing.

If the control circuit 103 determines in the processing step S818 that the sense signal VRs exceeding the reference threshold voltage Vcomp is detected within the section TS (if the pattern is (1, 1, x, x)), the process proceeds to a processing step S820.

In the processing step S820, when the level n of the main drive pulse P1 is the lowest level 0, the control circuit 103 cannot lower the level, maintains the level without changing the level, and returns to the processing step S601 (step S824).

If it is determined in the processing step S820 that the rank N of the main drive pulse P1 is not the lowest rank 0, the control circuit 103 adds 1 to the number N of consecutive generations (step S821), determines whether the number N has reached a predetermined number (80 in the present embodiment) (step S822), returns to the processing step S601 without changing the rank of the main drive pulse P1 if the predetermined number has not been reached (step S824), lowers the rank of the main drive pulse P1 by 1 if the predetermined number has been reached, resets the number N of consecutive generations to 0, and returns to the processing step S601 (step S823).

The stepping motor control circuit according to embodiment 3 is characterized by including a 3 rd mode in addition to the 1 st and 2 nd modes, wherein in the 3 rd mode, a driving pulse corresponding to a rotation condition of the stepping motor 108 is selected from a plurality of types of main driving pulses P1 (2 nd main driving pulse group) having smaller energy than the main driving pulse P1 (1 st main driving pulse group) in the 2 nd mode and a correction driving pulse P2 having larger energy than the plurality of types of main driving pulses P1 to drive the stepping motor 108, and the control unit maintains the driving state of the 1 st mode when the rotation condition in the 1 st mode by the main driving pulse P1 shows pulse maintenance or pulse rise, and switches to the 3 rd mode to drive when the rotation condition in the 1 st mode by the main driving pulse shows pulse fall.

Here, the following configurations are possible:

in the 2 nd mode, the detection section that detects the rotation condition of the stepping motor 108 is the 1 st detection section divided into the following sections: a 1 st section T1 immediately after the driving of the main drive pulse P1, a 2 nd section following the 1 st section, and a 3 rd section following the 2 nd section, wherein in the normal driving state, the 1 st section is a section in which the forward rotation state of the rotor 202 is determined in a 3 rd quadrant of a space around the rotor 202, the 2 nd section is a section in which the first forward rotation state and the first reverse rotation state of the rotor 202 are determined in the 3 rd quadrant, and the 3 rd section is a section in which the rotation state after the first reverse rotation of the rotor 202 is determined in the 3 rd quadrant,

in the 1 st and 3 rd modes, the detection section that detects the rotation condition of the stepping motor 108 is the 2 nd detection section divided into the following sections: a 4 th section T11 corresponding to the 1 st section T1, a 5 th section TS corresponding to a front region of the 2 nd section T2, a 6 th section T21 corresponding to a rear region of the 2 nd section T2, and a 7 th section T3 corresponding to the 3 rd section T3,

the control unit switches to the 3 rd mode to drive when the sensing signal exceeding the reference threshold voltage is detected within the 5 th section TS when the 1 st mode is driven with the main drive pulse.

Further, the following may be configured: the control unit continues the driving of the 1 st mode when the induction signal exceeding the reference threshold voltage is not detected within the 5 th section TS while the driving is performed with the main driving pulse in the 1 st mode.

Further, the following may be configured: the main drive pulse used in the 1 st mode is one of a plurality of types of main drive pulses used in the 3 rd mode (for example, a main drive pulse having the largest energy among the plurality of types of main drive pulses).

Further, the following may be configured: the control unit switches to the 2 nd mode to drive the stepping motor when detecting that the voltage of the secondary battery 113 detected by the voltage detection circuit 112 is equal to or lower than the predetermined switching voltage while driving in the 3 rd mode.

Therefore, according to embodiment 3, the main drive pulse corresponding to the voltage of the secondary battery and the rotation state of the stepping motor is used for driving, thereby preventing the occurrence of the non-rotation and suppressing the energy consumption.

When the voltage of the secondary battery 113 is lowered to the switching voltage or less, the mode 2 operation is performed, and when the voltage of the secondary battery 113 exceeds the switching voltage, the mode 1 operation is switched to be driven, and when the rotation is fast (the 5 th section TS is "1"), it is determined that the voltage is further increased, and the mode 3 operation is performed. This makes it possible to accurately determine the rotation state. Further, since the driving can be performed by switching to the main drive pulse of appropriate energy, power saving can be achieved.

Further, according to the analog electronic timepiece of embodiment 3, since the driving is performed by the main drive pulse corresponding to the voltage of the secondary battery and the rotation state of the stepping motor, it is possible to prevent the occurrence of the non-rotation and to suppress the energy consumption, and thus, it is possible to perform the accurate needle movement and the like.

In the above embodiments, the solar cell 114 is built in as the charging means for the secondary battery 113, but the charging means other than the solar cell 114, such as an automatic winding or manual winding charging means, may be used, or the charging means may be configured separately from the analog electronic timepiece.

In addition, it is also applicable to a stepping motor that drives components other than the time hand and the calendar.

In addition, although an electronic timepiece has been described as an example of application of the stepping motor, the stepping motor may be applied to an electronic device using a motor.

Industrial applicability

The stepping motor control circuit of the present invention can be applied to various electronic devices using a stepping motor.

The electronic timepiece of the present invention is applicable to various analog electronic timepieces with a calendar function, such as an analog electronic timepiece with a calendar function and an analog electronic timepiece with a calendar function.

Claims

1. A stepping motor control circuit, comprising:

a secondary battery as a power source that supplies at least electric power to the stepping motor;

a voltage detection unit that detects a voltage of the secondary battery;

a rotation detection unit that detects a rotation condition of the stepping motor; and

a control unit that drives the stepping motor in a 1 st mode or a 2 nd mode, in the 1 st mode, a drive pulse corresponding to a rotation condition of the stepping motor is selected from 1 kind of main drive pulses and correction drive pulses having energy larger than that of the 1 kind of main drive pulses to drive the stepping motor, in the 2 nd mode, a drive pulse corresponding to a rotation condition of the stepping motor is selected from a plurality of kinds of main drive pulses and correction drive pulses having energy larger than that of the plurality of kinds of main drive pulses to drive the stepping motor,

the control unit switches to one of the 1 st mode and the 2 nd mode to drive the stepping motor according to whether the voltage of the secondary battery detected by the voltage detection unit exceeds a predetermined switching voltage.

2. The stepping motor control circuit according to claim 1,

the control unit switches the switching voltage to a higher voltage when the rotation detection unit detects that the stepping motor is not rotating while driving in the 1 st mode.

3. The stepping motor control circuit according to claim 1,

the control unit performs pulse-up of a main drive pulse when the rotation detection unit detects that the stepping motor can be rotated but there is no energy margin during driving in the 2 nd mode.

4. The stepping motor control circuit according to claim 1,

the main drive pulse used in the 1 st mode is a main drive pulse of maximum energy among the main drive pulses used in the 2 nd mode.

5. The stepping motor control circuit according to claim 1,

the stepping motor control circuit has a 3 rd mode in which a driving pulse corresponding to a rotation condition of the stepping motor is selected from a plurality of types of main driving pulses having smaller energy than the main driving pulse in the 2 nd mode and a correction driving pulse having larger energy than the plurality of types of main driving pulses to drive the stepping motor,

the control unit maintains the driving state of the 1 st mode when the rotation state when the driving with the main driving pulse in the 1 st mode appears to be pulse maintenance or pulse rising, and switches to the 3 rd mode for driving when the rotation state when the driving with the main driving pulse in the 1 st mode appears to be pulse falling.

6. The stepping motor control circuit according to claim 5,

in the 2 nd mode, a detection section that detects the rotation condition of the stepping motor is a 1 st detection section divided into: a 1 st section immediately after the driving of the main drive pulse, a 2 nd section following the 1 st section, and a 3 rd section following the 2 nd section, wherein in the normal driving state, the 1 st section is a section in which a forward rotation state of the rotor is determined in a 3 rd quadrant of a space around the rotor, the 2 nd section is a section in which a first forward rotation state and a first reverse rotation state of the rotor are determined in a 3 rd quadrant, and the 3 rd section is a section in which a rotation state after a first reverse rotation of the rotor is determined in a 3 rd quadrant,

in the 1 st and 3 rd modes, a detection section that detects the rotation condition of the stepping motor is a 2 nd detection section divided into: a 4 th section corresponding to the 1 st section, a 5 th section corresponding to a front side region of the 2 nd section, a 6 th section corresponding to a rear side region of the 2 nd section, and a 7 th section corresponding to the 3 rd section,

the control unit switches to the 3 rd mode to drive when the sensing signal exceeding the reference threshold voltage is detected within the 5 th interval when the driving is performed with the main driving pulse in the 1 st mode.

7. The stepping motor control circuit according to claim 6,

the control unit continues the driving of the 1 st mode when the induction signal exceeding the reference threshold voltage is not detected in the 5 th section while the driving is performed with the main driving pulse in the 1 st mode.

8. The stepping motor control circuit according to claim 5,

the main drive pulse used in the 1 st mode is one of a plurality of kinds of main drive pulses used in the 3 rd mode.

9. The stepping motor control circuit according to claim 5,

the control unit switches to the 2 nd mode to drive the stepping motor when detecting that the voltage of the secondary battery detected by the voltage detection unit is equal to or lower than the predetermined switching voltage while driving in the 3 rd mode.

10. An analog electronic timepiece comprising: a stepping motor that rotationally drives the time hand; and a control unit for controlling the stepping motor, the analog electronic timepiece being characterized in that,

as a control unit for controlling the stepping motor, the stepping motor control circuit according to claim 1 is used.