HK1172101A - Motor drive device, timepiece device, and electronic device - Google Patents

Description

Motor drive device, timepiece device, and electronic apparatus

Technical Field

The invention relates to a motor driving device, a timepiece device, and an electronic apparatus.

Background

An electronic timepiece (timepiece device) using a solar cell or the like as a primary power supply unit is generally known. As the electronic timepiece described above, for example, there is an analog electronic timepiece as follows: a secondary battery (secondary power supply unit) is charged with a voltage generated by a primary power supply, and a motor drive pulse is output from a clock circuit using the charged power of the secondary battery to rotationally drive a motor for needle travel.

In the electronic timepiece as described above, the output voltage of the solar cell varies greatly depending on the intensity of light, and as a result, the power supply voltage applied to the timepiece circuit also varies, and the operation of the timepiece circuit is unstable. For this reason, for example, in patent document 1, the power supply voltage of the timepiece circuit is detected before the motor is driven, whether the power supply voltage applied to the timepiece circuit is a high voltage or a low voltage is determined, and an appropriate pulse width is selected based on the determination result of the high voltage/low voltage.

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

However, the technique described in patent document 1 has the following problems. That is, in this technique, the power supply voltage of the timepiece circuit is detected before the motor is driven, and the motor drive pulse (high-voltage pulse or low-voltage pulse) is selected. Therefore, when the charging state changes due to the start or end of charging the secondary battery during the motor driving and the power supply voltage of the timepiece circuit changes abruptly, the selected motor driving pulse is no longer an appropriate pulse, and there is a possibility that malfunction of the motor such as the motor not rotating may occur.

Here, in the case of detecting the non-rotation of the motor by the rotation detection technique, the following manner may also be considered: the motor is rotated by using a drive pulse having a pulse width sufficient for reliably driving the motor, and a timing error caused by the non-rotation of the motor is corrected. However, in the above-described rotation detection technique, the rotation/non-rotation of the motor is detected from the waveform of the voltage output to the motor terminal after the drive pulse is output, but this is premised on a relatively slow voltage change. Therefore, in the rotation detection technique as described above, when a solar cell or the like is used, the rotation detection technique cannot function normally when the voltage changes rapidly as in the case of the start or end of charging of the secondary battery.

That is, in the above two techniques, there are problems as follows: when the state of charge of the secondary battery changes during the driving of the motor and the power supply voltage changes rapidly, the motor cannot be driven reliably.

Disclosure of Invention

The present invention has been made in view of the above problems, and an object thereof is to provide a motor driving device, a timepiece device, and an electronic apparatus: even if the state of charge of the secondary battery (secondary power supply unit) changes during the driving of the motor and the power supply voltage changes rapidly, the motor can be driven reliably.

The present invention has been made to solve the above-mentioned problems, and one aspect of the present invention provides a motor driving device including: a charge detection unit that detects a charge state of a secondary power supply unit that is charged by electromotive force of a primary power supply unit, the charge state indicating whether or not the secondary power supply unit is being charged; and a control unit that generates a 1 st drive pulse for motor driving, and generates a 2 nd drive pulse for motor driving when the charging state detected by the charging detection unit is different before and after the 1 st drive pulse is output.

In the motor driving device according to an aspect of the present invention, the 2 nd driving pulse is a driving pulse having a pulse width wider than the 1 st driving pulse.

In the motor driving device according to an aspect of the present invention, the 2 nd drive pulse is a drive pulse having a pulse width of at least a sufficient degree necessary for rotating the motor.

In addition, according to an aspect of the present invention, the motor driving device includes a battery voltage detection unit that detects an output voltage of the secondary power supply unit, and the control unit changes a pulse width of the 1 st driving pulse in accordance with a detection result of the battery voltage detection unit.

In the motor drive device according to the aspect of the invention, the control unit may change a pulse width of the 1 st drive pulse based on the output voltage detected by the battery voltage detection unit and a predetermined switching point, and the control unit may not generate the 2 nd drive pulse when the output voltage detected by the battery voltage detection unit does not cross the predetermined switching point before and after the 1 st drive pulse is output.

In the motor drive device according to the aspect of the present invention, the primary power supply unit is a solar battery.

One aspect of the present invention provides a timepiece device including the motor drive device.

One aspect of the present invention provides an electronic device including the motor drive device.

According to the present invention, even when the state of charge of the secondary battery changes during the driving of the motor and the power supply voltage changes rapidly, the motor can be driven reliably.

Drawings

Fig. 1 is a schematic block diagram showing a configuration of a timepiece device including a motor drive device according to an embodiment of the present invention.

Fig. 2 is a waveform diagram showing the 1 st driving pulse supplied to the motor.

Fig. 3 is a waveform diagram showing the output voltage of the secondary battery.

Fig. 4 is a circuit diagram showing a detailed configuration of the charge detection backflow prevention unit.

Fig. 5 is a flowchart showing a pulse selection control process in the present embodiment.

Fig. 6 is a timing chart showing an example of the operation of the pulse selection control in the present embodiment.

Fig. 7 is a flow chart 2 showing another example of the pulse selection control process in the present embodiment.

Fig. 8 is a timing chart 2 showing another example of the operation of the pulse selection control in the present embodiment.

Fig. 9 is a 3 rd timing chart showing another example of the operation of the pulse selection control in the present embodiment.

Fig. 10 is a 4 th timing chart showing another example of the operation of the pulse selection control in the present embodiment.

Description of the symbols

1: a solar cell; 2: a secondary battery; 3: an oscillation control unit; 4: a quartz resonator; 5: a motor drive control section; 6: a motor; 7: a Switch (SW); 8: a battery voltage detection unit; 9: a charge detection reverse flow prevention section; 10: a power consumption control unit; 11: a pulse selection control unit; 12: an overcharge protection unit; 91: a diode; 92: a comparator; 100: a motor drive device; 200: a clock.

Detailed Description

An electronic device (for example, a timepiece device) having a motor drive device according to an embodiment of the present invention will be described below with reference to the drawings.

[ embodiment 1 ]

Fig. 1 is a schematic block diagram showing a configuration of a timepiece device (hereinafter referred to as a timepiece) having a motor drive device according to an embodiment of the present invention.

In the figure, the timepiece 200 includes: a solar cell 1, a secondary cell 2, and a motor drive device 100. Further, the motor drive device 100 includes: an oscillation control unit 3, a quartz resonator 4, a motor drive control unit 5, a time-use (needle travel-use) motor 6, a Switch (SW)7, a battery voltage detection unit 8, a charge detection backflow prevention unit 9, a power consumption control unit 10, a pulse selection control unit 11, and an overcharge protection unit 12. The timepiece 200 is, for example, an analog display type electronic timepiece, and the motion-work motor 6 is a stepping motor.

The functions of the respective parts in the timepiece 200 will be described below in sequence with reference to fig. 1.

The anode terminal of the solar cell 1 (primary power supply unit) is connected to the power supply line VDD, and the cathode terminal is connected to the power supply line SVSS. The negative terminal of the solar cell 1 is connected to the charge detection backflow prevention unit 9. The solar cell 1 generates an electromotive force by light. The solar cell 1 charges the secondary cell 2 via the charge detection backflow prevention unit 9. In addition, the solar cell 1 supplies power to each part of the timepiece 200 via the power supply line VDD. Here, the power supply line VDD is a VDD ground line and represents a reference potential of the entire timepiece 200.

The anode terminal of the secondary battery 2 (secondary power supply unit) is connected to a power supply line VDD, and the cathode terminal is connected to a power supply line VSS. The cathode terminal of the secondary battery 2 is connected to the charge detection backflow prevention unit 9. The secondary battery 2 is charged by the electromotive force of the solar battery 1 via the charge detection backflow prevention unit 9. In addition, the secondary battery 2 supplies power to each part of the timepiece 200 via the power supply line VDD.

The oscillation control unit 3 is connected to the quartz resonator 4, and oscillates and generates a basic clock signal used for time measurement. The oscillation control unit 3 controls the oscillation operation of the basic clock signal based ON a constant voltage ON (ON)/OFF (OFF) signal supplied from the power consumption control unit 10. Here, for example, when the constant voltage on/off signal is in the H (high) state, the oscillation control section 3 stops the oscillation of the basic clock signal. For example, when the constant voltage on/off signal is in the L (low) state, the oscillation control unit 3 oscillates the basic clock signal.

The oscillation control section 3 supplies the generated basic clock signal to the motor drive control section 5. The frequency of the basic clock signal generated by the oscillation control unit 3 is, for example, 32.768 kHz. The quartz resonator 4 is connected to the oscillation control unit 3, and oscillates and generates a basic clock signal.

The motor drive control unit 5 controls a timepiece operation for counting time based on the basic clock signal supplied from the oscillation control unit 3. The timepiece operation includes an operation of driving a motor (M)6, and the motor (M)6 moves a hand of the timepiece 200 that displays the time. That is, the motor drive control unit 5 supplies a predetermined drive pulse to the motor 6 to control the driving of the motor 6.

The motor drive control unit 5 is connected to a pulse selection control unit 11 of the power consumption control unit 10 via a control signal line. The motor drive control unit 5 outputs a drive timing signal output every 1 second and a pulse end signal indicating that the supply of the drive pulse to the motor 6 has been completed to the pulse selection control unit 11 via the control signal line. The motor drive control unit 5 receives a pulse generation request signal from the pulse selection control unit 11 via a control signal line.

Here, referring to fig. 2, a driving pulse supplied to the motor 6 is explained. Fig. 2 is a waveform diagram showing the 1 st drive pulse supplied to the motor 6.

In the present embodiment, 3 kinds of drive pulses are used as the drive pulses supplied to the motor 6. That is, the 1 st drive pulse mainly used for driving the motor 6 and the 2 nd drive pulse as the drive pulse for timing correction are used, and the 2 nd drive pulse has a sufficient pulse width necessary for reliably driving the motor.

Regarding the 1 st drive pulse, there is P1 that differs in pulse width_APulse sum P1_BThe pulse 2 is used so as to be able to cope with photovoltaic power generation having a large voltage fluctuation range, and the 1 st drive pulse is used in a switched manner in accordance with the output voltage of the secondary battery 2 as will be described later. That is, the pulse width of the 1 st drive pulse is changed in accordance with the detection result of the battery voltage detecting unit 8 that detects the output voltage of the secondary battery 2.

Specifically, the motor drive control unit 5 uses P1 when the output voltage of the secondary battery 2 is equal to or higher than a predetermined switching point CT (for example, 1.5V)_APulse, at less than 1.5V, using P1_BAnd (4) pulse. Thus, as shown in FIG. 2, P1_AThe pulse is set to a pulse width ratio P1_BShort pulse and pulse height ratio P1_BPulse height, P1_BThe pulse is set to a pulse width ratio P1_APulse length and pulse height ratio P1_AThe pulse is low. In addition, P1_APulse sum P1_BThe pulse width of the pulse is the minimum pulse width that can drive the motor 6 according to the output voltage of the secondary battery 2. This reduces power consumption of the timepiece 200 and the motor drive device 100.

In this embodiment, the 2 nd drive pulse has a pulse width much larger than P1_APulse sum P1_BP2 pulse, described later.

The P2 pulse has a larger pulse width than the 1 st drive pulse (P1)_APulse or P1_BPulse) a wider pulse width drive pulse. That is, the P2 pulse is a drive pulse having a pulse width more than a sufficient degree necessary for rotating the motor. That is, the P2 pulse is a correction drive pulse having a pulse width having an effective value capable of sufficiently driving the motor.

Here, the switching point CT will be described with reference to fig. 3. Fig. 3 is a waveform diagram showing the output voltage of the secondary battery 2.

As shown in fig. 3, the secondary battery 2 repeats discharge (power consumption) and charge, and the fully charged output voltage is 1.8V to 2.6V or more, the average output voltage is 1.3V to 1.4V, and the output voltage in the end state is 1.0V. The output voltage 1.5V is set in advance as the switching point CT, for example. That is, the switching point CT is for the usage P1_APulse as drive pulse of motor 6 and use of P1_BThe pulse is an output voltage point of the secondary battery 2 that switches the driving method of the driving pulse of the motor 6.

The motor drive control unit 5 includes a pulse generation unit that generates the above-mentioned P1_APulse, P1_BPulse and P2 pulse. This unit may be configured by software using a CPU, or may be configured by hardware that is only a logic circuit. The motor drive control unit 5 receives the pulse generation request signal output from the pulse selection control unit 11, and generates P1 from the pulse generation means_APulse, P1_BEither one of the pulse and the pulse P2 is supplied to the motor 6. The motor drive control unit 5 is described in P1_APulse, P1_BAfter either one of the pulse and the P2 pulse is supplied to the motor 6, a pulse end signal is output to the pulse selection control unit 11.

The motor drive control unit 5 shifts the timepiece 200 to the low consumption mode in response to the low consumption mode signal supplied from the power consumption control unit 10. Specifically, when the low consumption mode signal is in the H state, the motor drive control unit 5 shifts the timepiece 200 to the low consumption mode. On the other hand, when the low consumption mode signal is in the L state, the motor drive control unit 5 shifts the timepiece 200 from the low consumption mode to the normal operation mode.

The motor drive control unit 5 detects the rotation of the motor 6, and determines whether or not the needle is normally moved (rotation detection technique). When determining that the movement is not performed normally, the motor drive control unit 5 drives the motor 6 again to instruct the hand of the timepiece to a correct time.

The motor 6 rotates the rotor upon receiving a drive pulse supplied from the motor drive control unit 5, and moves the hand of the timepiece 200. That is, the motor 6 is a time motor for counting time. The motor 6 is a motor that stops the motor at a fixed position and can normally rotate only 180 degrees by one drive. The drive torque of the drive motor 6 is determined by the voltage and the pulse width of the drive pulse. When the driving torque of the 1 st driving pulse is small, the motor 6 may not be rotated by 180 degrees. On the other hand, when the driving torque of the 1 st driving pulse is large, the rotational force of the motor 6 may be too large, and the rotational position may be returned to the original position before the rotation by the reverse movement from the rotational position of 180 degrees.

When the motor 6 is driven by the pulse P2, the motor is rotated to the 180-degree rotational position and then the rotational position is maintained at the 180-degree rotational position by applying the driving torque. Therefore, the motor 6 does not return to the original position before rotation due to the reverse movement, that is, can reliably rotate 180 degrees by the P2 pulse. The reason why the timepiece 200 does not always use the P2 pulse to move the hand is that the P2 pulse increases power consumption.

One terminal of the switch 7 is connected to the motor drive control unit 5, and the other terminal is connected to the power supply line VDD. The switch 7 is a handle switch of the timepiece 200. When the handle is pulled out of the timepiece 200, the switch 7 is, for example, in a conductive state, and when the handle is pushed into the timepiece 200, the switch 7 is, for example, in a non-conductive state. When the watch bezel is pulled out, the timepiece 200 stops the movement of the hands, and is in a state in which the time setting is possible. That is, when the switch 7 is in the on state, the motor drive control unit 5 stops the driving of the motor 6.

The battery voltage detection unit 8 detects the output voltage (output potential difference) of the secondary battery 2 using the detection sampling signal supplied from the power consumption control unit 10 as a trigger. When detecting that the output voltage of the secondary battery 2 is less than the predetermined threshold, the battery voltage detection unit 8 outputs a low consumption mode detection signal to the power consumption control unit 10 as a detection result. Specifically, when the output voltage of the secondary battery 2 is less than a predetermined threshold, the low consumption mode detection signal is in the H state, and when the output voltage of the secondary battery 2 is equal to or greater than the predetermined threshold, the low consumption mode detection signal is in the L state. In addition, the predetermined threshold value is a value higher than a lower limit voltage at which the motor 6 can be driven by a predetermined voltage amount.

The battery voltage detection unit 8 detects whether or not the output voltage of the secondary battery 2 is equal to or higher than a predetermined switching point CT (for example, 1.5V), and outputs a pulse selection signal corresponding to the detection result to the pulse selection control unit 11. That is, the pulse selection signal is in, for example, the H state when the output voltage of the secondary battery 2 is equal to or higher than a predetermined switching point CT (for example, 1.5V), and in the L state when the output voltage is lower than the switching point CT.

The charge detection backflow prevention unit 9 (charge detection unit) detects the state of charge of the secondary battery 2. The charge state here indicates whether or not the secondary battery 2 is being charged. Specifically, the charge detection backflow prevention unit 9 detects, for example, a non-charging state indicating a state in which the output voltage (output potential difference) of the solar cell 1 is equal to or less than the output voltage (output potential difference) of the secondary cell 2. When detecting a non-charging body, the charge detection backflow prevention unit 9 outputs a charge detection signal to the power consumption control unit 10 as a detection result. In the case of being in the non-charging state, the charge detection signal is in the H state. On the other hand, when the battery is in the in-charge state indicating a state in which the output voltage of the solar cell 1 is larger than the output voltage of the secondary battery 2, the charge detection signal is in the L state.

Fig. 4 is a circuit diagram showing a detailed configuration of the charge detection backflow prevention unit 9.

As shown in fig. 4, the charge detection backflow prevention unit 9 is composed of a diode 91 and a comparator 92. The diode 91 has a positive electrode connected to the power supply line VSS and a negative electrode connected to the power supply line SVSS. With this configuration, the charge detection backflow prevention unit 9 prevents a current from flowing backward from the secondary battery 2 to the solar battery 1 when the generated voltage of the solar battery 1 is lower than the battery voltage of the secondary battery 2.

One input terminal of the comparator 92 is connected to a power supply line SVSS connected to the cathode terminal of the solar cell 1, and the other input terminal is connected to a power supply line VSS connected to the cathode terminal of the secondary cell 2. The output of the comparator 92 is a charge detection signal. When the output voltage of the solar cell 1 is equal to or lower than the output voltage of the secondary cell 2 (when the battery is not in a charging state), the comparator 92 outputs the H state to the power consumption control unit 10 as a charge detection signal. When the output voltage of the solar cell 1 is higher than the output voltage of the secondary cell 2, the comparator 92 outputs the L state to the power consumption control unit 10 as a charge detection signal.

The power consumption control unit 10 determines whether or not the output voltage of the secondary battery 2 is equal to or less than the predetermined threshold value based on the detection result (low consumption mode detection signal) of the battery voltage detection unit 8. Then, the power consumption control unit 10 determines whether or not the solar cell 1 is in a non-charging state indicating a state in which the output voltage of the solar cell 1 is equal to or lower than the output voltage of the secondary cell 2, based on the detection result (charge detection signal) of the charge detection backflow prevention unit 9. The power consumption control unit 10 shifts to the low consumption mode based on the low consumption mode detection signal and the charge detection signal.

Here, the low consumption mode is, for example, a state as follows: the motor drive control section 5 stops the drive of the motor 6, and the oscillation control section 3 stops the output of the basic clock signal. Therefore, when the mode is shifted to the low consumption mode, the power consumption control unit 10 causes the motor drive control unit 5 to stop the timepiece operation (the motion of the motor 6). When the mode is shifted to the low consumption mode, the power consumption control unit 10 stops the oscillation control unit 3 from generating the basic clock signal.

When it is determined that the charging state is not the non-charging state based on the charging detection signal, the power consumption control unit 10 shifts from the low consumption mode to a normal operation mode in which the timepiece operation is performed. Here, the normal operation mode is a state as follows: the oscillation control section 3 outputs a basic clock signal, and the motor drive control section 5 drives the motor 6.

The power consumption control unit 10 supplies the detection sampling signal to the battery voltage detection unit 8 as a trigger signal for detecting the output voltage of the secondary battery 2. The power consumption control unit 10 supplies a constant voltage on/off signal to the oscillation control unit 3 and a low consumption mode signal to the motor drive control unit 5. The power consumption control unit 10 performs control for shifting from the normal operation mode to the low consumption mode or control for shifting from the low consumption mode to the normal operation mode, by a constant voltage on/off signal and a low consumption mode signal.

The power consumption control unit 10 includes a pulse selection control unit 11.

The pulse selection control unit 11 (control unit) outputs a pulse generation request signal to the motor drive control unit 5 based on the drive timing signal, so as to generate P1 for motor drive at a predetermined timing (every 1 second)_APulse or P1_BAnd (4) pulse. Specifically, when the drive timing signal is obtained from the motor drive control unit 5, the pulse selection control unit 11 refers to the pulse selection signal from the battery voltage detection unit 8. When the pulse selection signal is in the H state, that is, when the output voltage of the secondary battery 2 is equal to or higher than the switching point CT (for example, 1.5V), the pulse selection control unit 11 outputs a pulse generation request signal to the motor drive control unit 5 to generate P1_AThe pulses serve as drive pulses for the motor 6. When the pulse selection signal is in the L state, that is, when the pulse selection signal is in the L state, the pulse selection control unit 11 controls the secondary battery2 is less than 1.5V, a pulse generation request signal is output to the motor drive control section 5 to generate P1_BThe pulses serve as drive pulses for the motor 6.

The pulse selection control unit 11 also performs control of P1 based on the detection result of the charge detection backflow prevention unit 9 that detects the state of charge of the secondary battery 2_APulse or P1_BState of charge before pulse output and P1_APulse or P1_BAnd comparing the charging states after the pulse is output. Then, the pulse selection control unit 11 performs control at P1_APulse or P1_BState of charge before pulse output and P1_APulse or P1_BWhen the state of charge after the pulse output is different, a pulse P2 is generated for driving the motor.

Specifically, the pulse selection control unit 11 monitors the charge detection signal, and outputs a pulse generation request signal to the motor drive control unit 5 based on the result of the monitoring to generate a P2 pulse as a drive pulse of the motor 6. That is, the pulse selection control unit 11 implements P1_APulse or P1_BBefore the generation request of pulse and implementing P1_APulse or P1_BAfter the generation request of the pulse, the state (H state/L state) of the charge detection signal is investigated, and if their states are different, a pulse generation request signal is output to generate a P2 pulse. The detailed operation of this point will be described later. The pulse selection control unit 11 detects that P1 is implemented based on the pulse end signal supplied from the motor drive control unit 5_APulse or P1_BThe state of charge (the state of the charge detection signal) after the request for generation of the pulse.

The overcharge protection unit 12 detects an output voltage (generated voltage) of the solar cell 1. The overcharge protection unit 12 short-circuits the power generation side in order to prevent the secondary battery 2 from being overcharged when the detected generated voltage of the solar cell 1 is equal to or higher than a predetermined threshold value (when the generated voltage is excessively large).

Next, the operation of the present embodiment will be described.

Fig. 5 is a flowchart showing a pulse selection control process in the present embodiment.

First, the pulse selection control unit 11 determines whether or not the output voltage of the secondary battery 2 is equal to or higher than a switching point CT (for example, 1.5V) based on the state (H state/L state) of the pulse selection signal supplied from the battery voltage detection unit 8 (step S101). The pulse selection control unit 11 executes the processing of step S101 based on the drive timing signal supplied from the motor drive control unit 5.

Next, the pulse selection control unit 11 selects P1 according to the determination result in step S101_APulse or P1_BThe pulse is used as a drive pulse of the motor 6 (step S102). That is, when the output voltage of the secondary battery 2 is 1.5V or more (the state of the pulse selection signal is H state), the pulse selection control unit 11 outputs a pulse generation request signal to the motor drive control unit 5 to generate P1_AThe pulses serve as drive pulses for the motor 6. When the output voltage of the secondary battery 2 is less than 1.5V (the state of the pulse selection signal is L state), the pulse generation request signal is output to the motor drive control unit 5 to generate P1_BThe pulses serve as drive pulses for the motor 6.

Next, the pulse selection control unit 11 determines the charging/non-charging state of the secondary battery 2 based on the state (H state/L state) of the charge detection signal output from the charge detection backflow prevention unit 9 (step S103). Then, the determination result at this time is recorded in the memory as the state a (step S104). Thereafter, the motor drive control unit 5 sets P1 selected in step S102 to P1_APulse or P1_BThe pulse is output to the motor 6 to drive the motor 6 (step S105).

After the motor 6 is driven, the pulse selection control section 11 determines the charging/non-charging state of the secondary battery 2 again based on the state (H state/L state) of the charge detection signal (step S106). The determination result at this time is set as state B. The pulse selection control unit 11 detects that the motor 6 is driven based on the pulse end signal supplied from the motor drive control unit 5, and executes the processing of step S106. In this way, the pulse selection control unit 11 determines the charging/non-charging state of the secondary battery 2 before and after driving of the motor 6. Then, the pulse selection control unit 11 compares the state a and the state B as the determination results (step S107).

If the result of comparing the state a and the state B is that they are the same, the pulse selection control process is ended, and if the result of comparing the state a and the state B is that they are different, the pulse selection control portion 11 outputs a pulse generation request signal to the motor drive control portion 5 to generate a P2 pulse as a drive pulse of the motor 6 (step S108), and the pulse selection control process is ended.

Next, the pulse selection control according to the present embodiment in the state transition in which the voltage drop due to the power consumption is caused again through the voltage rise due to the charging due to the voltage drop due to the power consumption will be described with reference to fig. 6.

Fig. 6 is a timing chart showing an example of the operation of the pulse selection control in the present embodiment. In the figure, the horizontal axis represents time, and the vertical axis represents the power supply voltage. In addition, the figure shows P1_APulse or P1_BPulses are supplied to the motor 6 every 1 second.

First, during a period from time T1 to around time T3, as shown by W1 in fig. 6, the output voltage (power supply voltage) of the secondary battery 2 is lower than the switching point CT (for example, 1.5V), and gradually decreases as the voltage decreases due to power consumption.

At time T1, the output voltage of the secondary battery 2 is lower than the switching point CT, and therefore the pulse selection signal output from the battery voltage detection unit 8 is in the L state. The pulse selection control unit 11 determines that the output voltage of the secondary battery 2 is lower than the switching point CT based on the state of the pulse selection signal (step S101 in fig. 5). By this determination, the pulse selection control unit 11 outputs a pulse generation request signal to the motor drive control unit 5 to generate P1_BThe pulse is used as a drive pulse of the motor 6 (step S102).

Since the secondary battery 2 is not charged at time T1, the charge detection signal from the charge detection backflow prevention unit 9 is in the H state, and the pulse selection control unit 11 determines that the secondary battery 2 is in the non-charging state (step S103). The determination result (state a) is recorded in the memory of the pulse selection control unit 11 (step S104).

After time T1, the motor drive control unit 5 generates P1 in response to a pulse generation request signal from the pulse selection control unit 11_BThe pulse is used as a drive pulse of the motor 6, thereby driving the motor 6 (step S105).

At outputted P1_BAt time T2 after the motor 6 is driven by the pulse, the pulse selection control unit 11 determines the charging/non-charging state of the secondary battery again from the charge detection signal (step S106, the determination result is state B). At time T2, it is also determined that the state is not in the charging state as at time T1, and therefore the result of comparing state a with state B is that they are the same (step S107). At this time, it is determined that the state of charge of the secondary battery 2 does not change during the motor driving and the power supply voltage does not change rapidly, and therefore, there is a low possibility of causing a motor malfunction such as the motor 6 not rotating. Therefore, the pulse generation request signal does not forcibly output the P2 pulse as the correction drive pulse.

At time T3 thereafter, it is also determined that the pulse selection signal is in the L state and the output voltage of the secondary battery 2 is lower than the switching point CT, and the pulse selection controller 11 outputs a pulse generation request signal to generate P1_BThe pulses serve as drive pulses for the motor 6. Since the secondary battery 2 is not charged, the charge detection signal continues to be in the H state, and the pulse selection control unit 11 determines that the secondary battery 2 is in the non-charging state (state a).

After time T3, motor drive control unit 5 outputs P1_BThe pulse is used as a drive pulse of the motor 6 to drive the motor 6.

At output P1_BAt time T4 after the motor 6 is driven by the pulse, the pulse selection control unit 11 determines the in-charge/non-in-charge state of the secondary battery 2 again based on the charge detection signal (determination result is state B). At time T4, unlike time T3, it is determined that the state is in the charged state, and the result of comparing state a with state B is that they are different. This is because, when passing through P1_BAt time T11 when the pulse drives the motor 6, light starts to be applied to the solar cell 1, and the secondary cell 2 changes from the non-charging state to the charging state, whereby the output voltage of the secondary cell 2 sharply increases as shown by W2 in fig. 6.

At this time, since the power supply voltage abruptly changes, a drive pulse (P1) selected in accordance with the power supply voltage before the motor is driven (time T3) may occur_BPulse) is no longer appropriate. In addition, the above-described rotation detection technique may not function properly. Therefore, there is a high possibility that the motor malfunctions, such as the motor cannot rotate. Therefore, the motor drive device 100 operates to forcibly supply the P2 pulse as the correction drive pulse to the motor 6. That is, the pulse selection control section 11 outputs a pulse generation request signal to the motor drive control section 5 to generate a P2 pulse as a drive pulse of the motor 6. Thus, after the time T4, the motor drive control unit 5 supplies the P2 pulse to the motor 6, and as a result, the motor 6 is driven to rotate, and the timing error caused by the non-rotation of the motor is corrected.

The voltage after the start of charging rapidly rises (W2 in fig. 6), and the output voltage (power supply voltage) of the secondary battery 2 continues to rise slowly due to charging as shown by W3 in fig. 6 in the vicinity of the subsequent time T5. At this time, the output voltage of the secondary battery 2 is higher than the switching point CT (for example, 1.5V).

At time T5, since the output voltage of the secondary battery 2 is higher than the switching point CT, the pulse selection signal output from the battery voltage detection unit 8 is in the H state (step S101). As a result, the pulse selection control unit 11 outputs a pulse generation request signal to the motor drive control unit 5 to generate P1_AThe pulse is used as a drive pulse of the motor 6 (step S102).

Since the secondary battery 2 is being charged at time T5, the charge detection signal from the charge detection backflow prevention unit 9 is in the L state, and the pulse selection control unit 11 determines that the secondary battery 2 is in the charging state (step S103). The determination result (state a) is recorded in the memory of the pulse selection control unit 11 (step S104).

After time T5, the motor drive control unit 5 outputs P1 in response to a pulse generation request signal from the pulse selection control unit 11_AThe pulse is used as a drive pulse of the motor 6 to drive the motor 6 (step S105).

At output P1_AAt time T6 after the motor 6 is driven by the pulse, the pulse selection control unit 11 determines the in-charge/non-in-charge state of the secondary battery 2 again based on the charge detection signal (step S106, the determination result is state B). At time T6, it is also determined that charging is underway in the same manner as at time T5, and therefore the result of comparing state a with state B is that they are the same (step S107). At this time, it is determined that the state of charge of the secondary battery 2 does not change during the motor driving and the power supply voltage does not change rapidly, and therefore, there is a low possibility of causing a motor malfunction such as the motor 6 not rotating. Therefore, the P2 pulse is not output by the pulse generation request signal.

At time T7 thereafter, it is also determined that the output voltage of the secondary battery 2 is higher than the switching point CT, and the pulse selection controller 11 outputs a pulse generation request signal to generate P1_AThe pulses serve as drive pulses for the motor 6. Then, the charge detection signal continues to be held in the L state, and the pulse selection control unit 11 determines that the secondary battery 2 is being charged (state a).

After time T7, motor drive control unit 5 outputs P1_AThe pulse is used as a drive pulse of the motor 6 to drive the motor 6.

At output P1_AAt time T8 after the motor 6 is driven by the pulse, the pulse is selectedThe control unit 11 determines the charging/non-charging state of the secondary battery 2 again from the charge detection signal (determination result is state B). At time T8, unlike time T7, it is determined that the state is not in the charging state, and the result of comparing state a with state B is that they are different. This is because, when passing through P1_AAt time T12 when the pulse-driven motor 6 is driven, the solar cell 1 is no longer irradiated with light, and the secondary cell 2 changes from the state of being charged to the state of not being charged, and the output voltage of the secondary cell 2 drops sharply as shown by W4 in fig. 6.

At this time, since the power supply voltage also changes rapidly, a drive pulse (P1) selected in accordance with the power supply voltage before the motor is driven (time T7) may occur_APulse) is no longer appropriate. In addition, the above-described rotation detection technique may not function properly. Therefore, there is a high possibility of causing a malfunction of the motor such as the motor 6 being unable to rotate. Therefore, the pulse selection control unit 11 outputs a pulse generation request signal to the motor drive control unit 5 to generate a P2 pulse for correction as a drive pulse of the motor 6. Thus, after the time T8, the motor drive control unit 5 supplies the P2 pulse to the motor 6, and as a result, the motor 6 is driven to rotate, and the timing error caused by the non-rotation of the motor is corrected.

Similarly to W1 of fig. 6, W5 of fig. 6 shows that the output voltage (power supply voltage) of the secondary battery 2 is lower than the switching point CT (for example, 1.5V), and gradually decreases as the voltage decreases due to power consumption. Therefore, in W5 of fig. 6, the pulse selection controller 11 performs the same processing as in W1 of fig. 6.

As described above, according to the present embodiment, the pulse selection control unit 11 checks and compares the time before and after the motor drive, that is, the time before and after the P1 is supplied to the motor 6_APulse or P1_BThe state of the charge detection signal before and after the pulse. Thus, the pulse selection control unit 11 can determine whether or not the state of charge of the secondary battery 2 has changed during the motor drive. For example, the pulse selection control unit 11 monitors the state of the charge detection signal, and if it is determined that the motor is not being charged before the motor is drivenIf the state is in the charging state after the motor drive, it can be determined that the charging is started during the motor drive. Further, if the pulse selection control unit 11 determines that the charging is in progress before the motor is driven and that the non-charging state is in progress after the motor is driven, it can be determined that the charging is completed during the motor is driven.

Further, in the present embodiment, when the charging state of the secondary battery is changed by starting or ending the charging during the motor driving and the power supply voltage is abruptly changed, the driving pulse selected in accordance with the power supply voltage before the motor driving is performed (P1)_APulse or P1_BPulse) may no longer be a suitable pulse and the rotation detection techniques described above may not function properly. Therefore, when the pulse selection control unit 11 determines that there is a possibility of an erroneous operation of the motor such as the motor not rotating, the timepiece 200 and the motor drive device 100 forcibly generate the P2 pulse as the drive pulse for correction to rotationally drive the motor 6. Thus, in the timepiece 200 and the motor drive device 100, even if the motor 6 does not rotate due to a rapid change in the power supply voltage caused by a change in the state of charge, the motor 6 can be reliably driven to rotate by the P2 pulse, and the time error caused by the non-rotation of the motor can be corrected. Therefore, in the timepiece 200 and the motor drive device 100, even when the charging state of the secondary battery 2 (secondary power supply unit) changes during the motor drive and the power supply voltage changes abruptly, the motor can be driven reliably.

In addition, according to an embodiment of the present invention, the motor drive device 100 includes: a charge detection backflow prevention unit 9 (charge detection unit) that detects a state of charge of the secondary battery 2 (secondary power supply unit) that is charged by an electromotive force of the solar battery 1 (primary power supply unit), the state of charge indicating whether or not the secondary battery 2 is being charged; and a pulse selection control unit (control unit) 11 for generating a 1 st drive pulse (P1)_APulse or P1_BPulse) for motor drive, and the charging state detected by the charging detection backflow prevention section 9 is different between before and after the output of the 1 st drive pulseIn this case, the 2 nd drive pulse (P2 pulse) is generated for motor driving.

Thus, the motor drive device 100 can reliably drive the motor even when the charging state of the secondary battery 2 (secondary power supply unit) changes during the driving of the motor and the power supply voltage changes abruptly.

In addition, the 2 nd driving pulse is a pulse having a higher driving voltage than the 1 st driving pulse (P1)_APulse or P1_BPulse) a wide pulse width. The 2 nd drive pulse is a drive pulse (P2 pulse) having a pulse width not less than a sufficient level required to rotate the motor.

Thus, the motor drive device 100 can reliably rotate the motor 6 by the 2 nd drive pulse (P2 pulse). Therefore, in motor drive device 100, even if the state of charge of the secondary battery changes during motor driving and the power supply voltage changes rapidly, the timing error caused by the non-rotation of the motor can be corrected reliably.

The motor drive device 100 further includes a battery voltage detection unit 8, and the battery voltage detection unit 8 detects an output voltage of the secondary battery 2 (secondary power supply unit). The pulse selection control unit 11 (control unit) changes the pulse width of the 1 st drive pulse in accordance with the detection result of the battery voltage detection unit 8.

Thus, the motor drive device 100 can set an optimum drive pulse width required for driving the motor 6 in accordance with the output voltage of the secondary battery 2 (secondary power supply unit). Therefore, the motor drive device 100 can reduce power consumption during the timepiece operation.

In the above embodiment, the primary power supply unit is a solar cell.

Thus, since the solar cell 1 can directly convert light energy into electric power, the number of components of the primary power supply unit can be reduced.

The timepiece 200 (timepiece device) includes the motor drive device 100.

This allows the timepiece 200 to expect the same effects as those of the motor drive device 100. That is, in the timepiece 200, even when the state of charge of the secondary battery 2 (secondary power supply unit) changes during the motor driving and the power supply voltage changes rapidly, the motor can be driven reliably. Further, the timepiece 200 can reliably move the hand and accurately time the time.

[ 2 nd embodiment ]

Next, another embodiment of the present invention will be described.

The timepiece 200 and the motor drive device 100 according to this embodiment have the same configuration as those of embodiment 1 shown in fig. 1. The timepiece 200 and the motor drive device 100 according to the present embodiment differ from those according to embodiment 1 in the pulse selection control process in the pulse selection control unit 11, and the pulse selection control process according to the present embodiment will be described below.

Fig. 7 is a flow chart 2 showing the pulse selection control process in the present embodiment.

First, the pulse selection control unit 11 determines whether or not the output voltage of the secondary battery 2 is equal to or higher than a switching point CT (for example, 1.5V) based on the state (H state/L state) of the pulse selection signal supplied from the battery voltage detection unit 8 (step S201). The pulse selection control unit 11 executes the processing of step S201 based on the drive timing signal supplied from the motor drive control unit 5.

Next, the pulse selection control unit 11 records the determination result (determination result of the power supply voltage) of whether or not the output voltage of the secondary battery 2 is equal to or higher than the switching point CT (for example, 1.5V) as the 1 st determination result in the memory (step S202).

Next, the pulse selection control unit 11 selects P1 according to the determination result in step S201_APulse or P1_BThe pulse is used as a drive pulse of the motor 6 (step S203). That is, the pulse selection control unit 11 controls the output voltage of the secondary battery 2 to be 1.5V or more (the state of the pulse selection signal)State H), a pulse generation request signal is output to the motor drive control unit 5 to generate P1_AThe pulses serve as drive pulses for the motor 6. When the output voltage of the secondary battery 2 is less than 1.5V (the state of the pulse selection signal is L state), the pulse generation request signal is output to the motor drive control unit 5 to generate P1_BThe pulses serve as drive pulses for the motor 6. That is, the pulse selection control unit 11 changes the pulse width of the 1 st drive pulse in accordance with the output voltage detected by the battery voltage detection unit 8 and a predetermined switching point CT (for example, 1.5V).

Next, the pulse selection control unit 11 determines the charging/non-charging state of the secondary battery 2 based on the state (H state/L state) of the charge detection signal output from the charge detection backflow prevention unit 9 (step S204). Then, the determination result at this time is recorded in the memory as the state a (step S205). Thereafter, the motor drive control section 5 sets P1 selected in step S203 to P1_APulse or P1_BThe pulse is output to the motor 6 to drive the motor 6 (step S206).

After the motor 6 is driven, the pulse selection control part 11 determines the charging/non-charging state of the secondary battery 2 again based on the state of the charge detection signal (H state/L state) (step S207). The determination result at this time is set as state B. The pulse selection control unit 11 detects that the motor 6 is driven based on the pulse end signal supplied from the motor drive control unit 5, and executes the processing of step S207. In this way, the pulse selection control unit 11 determines the charging/non-charging state of the secondary battery 2 before and after driving of the motor 6. Then, the pulse selection control unit 11 compares the state a and the state B as the determination results (step S208).

If the result of comparing the state a and the state B is that they are the same, the pulse selection control section 11 ends the pulse selection control process, and if the result of comparing the state a and the state B is that they are different, the pulse selection control section 11 proceeds to step S209 to perform the process.

Next, in step S209, the pulse selection control unit 11 determines whether or not the output voltage of the secondary battery 2 is equal to or higher than the switching point CT (for example, 1.5V) again based on the state (H state/L state) of the pulse selection signal supplied from the battery voltage detection unit 8.

Next, the pulse selection control unit 11 records the determination result (determination result of the power supply voltage) of whether or not the output voltage of the secondary battery 2 is equal to or higher than the switching point CT (for example, 1.5V) as the 2 nd determination result in the memory (step S210).

Next, the pulse selection control unit 11 determines whether or not the 1 st determination result recorded in the memory in step S202 is equal to the 2 nd determination result recorded in the memory in step S210 (step S211). The pulse selection control unit 11 proceeds to step S212 to perform the processing when the 1 st determination result is different from (not equal to) the 2 nd determination result, and ends the pulse selection control processing when the 1 st determination result is equal to the 2 nd determination result. That is, in the case where the output voltage detected by the battery voltage detecting portion 8 does not cross the predetermined switching point CT (for example, 1.5V) before and after the 1 st drive pulse is output, the pulse selection control portion 11 does not generate the 2 nd drive pulse (P2 pulse).

Next, in step S212, the pulse selection control unit 11 outputs a pulse generation request signal to the motor drive control unit 5 to generate a P2 pulse as a drive pulse of the motor 6, and ends the pulse selection control process.

Next, the pulse selection control according to the present embodiment in the state transition in which the voltage drop due to the power consumption is caused, the voltage rise due to the charging is caused, and the voltage drop due to the power consumption is caused again will be described with reference to fig. 8 to 10.

Fig. 8 is a timing chart 2 showing an example of the operation of the pulse selection control in the present embodiment. In the figure, as in fig. 6, the horizontal axis represents time, and the vertical axis represents the power supply voltage. In addition, the figure shows P1_APulse or P1_BPulses are supplied to the motor 6 every 1 second.

In fig. 8, a process when a predetermined switching point CT (for example, 1.5V) is crossed before and after the 1 st drive pulse is output will be described.

First, in W1a, W3a, and W5a of fig. 8, the state of charge is equal before and after the output of the 1 st drive pulse (state a is equal to state B), and therefore, as shown in step S208 of fig. 7, the 1 st drive pulse (P1) is output_APulse or P1_BPulse), the pulse selection control section 11 does not cause the motor drive control section 5 to generate the 2 nd drive pulse (P2 pulse).

Next, the operation of the pulse selection control when the output voltage of the secondary battery 2 is shifted from a state lower than the switching point CT to a state higher than the switching point CT during the period from the time T3 to the time T4 will be described.

At this time, at time T3, the output voltage of the secondary battery 2 is less than the switching point CT (e.g., 1.5V), and therefore the pulse selection control part 11 causes the motor drive control part 5 to output (generate) P1_BThe pulse serves as the 1 st drive pulse. Here, since the state of charge (state a) at time T3 is different from the state of charge (state B) at time T4, pulse selection control unit 11 determines that state a is different from state B (step S208), and determines the output voltage of secondary battery 2 again (step S209). Further, at this time, as shown by W2a in fig. 8, since the output voltage of the secondary battery 2 changes across the switching point CT between the time T3 and the time T4, the pulse selection controller 11 determines that the 1 st determination result is different from the 2 nd determination result (step S211). As a result, the pulse selection control unit 11 causes the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse) (step S212).

Next, the operation of the pulse selection control when the output voltage of the secondary battery 2 shifts from a state higher than the switching point CT to a state lower than the switching point CT during the period from the time T7 to the time T8 will be described.

At this time, at time T7, since the output voltage of the secondary battery 2 is equal to or higher than the switching point CT (for example, 1.5V), the pulse selection controller 11 causes the motor drive controller 5 to output (generate) P1_AThe pulse serves as the 1 st drive pulse. Here, since the state of charge (state a) at time T7 is different from the state of charge (state B) at time T8, pulse selection control unit 11 determines that state a is different from state B (step S208), and determines the output voltage of secondary battery 2 again (step S209). Further, at this time, as shown by W4a in fig. 8, since the output voltage of the secondary battery 2 changes across the switching point CT between the time T7 and the time T8, the pulse selection controller 11 determines that the 1 st determination result is different from the 2 nd determination result (step S211). As a result, the pulse selection control unit 11 causes the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse) (step S212).

Fig. 9 is a 3 rd timing chart showing an example of the operation of the pulse selection control in the present embodiment. In the figure, the horizontal axis represents time and the vertical axis represents the power supply voltage, as in fig. 8. In addition, the figure shows the 1 st drive pulse (P1)_APulse) is supplied to the motor 6 every 1 second.

Fig. 9 illustrates a process when the output voltage of the secondary battery 2 is higher than a predetermined switching point CT (for example, 1.5V) and does not cross the predetermined switching point CT before and after the output of the 1 st drive pulse, as shown in W1b to W5 b.

In W1b to W5b of fig. 9, since the output voltage of the secondary battery 2 is higher than the switching point CT, the pulse selection controller 11 causes the motor drive controller 5 to output (generate) P1_AThe pulse serves as the 1 st drive pulse. At this time, in the 1 st drive pulse (P1)_APulse) before and after the output does not cross the predetermined switching point CT, the pulse selection control section 11 does not cause the motor drive control section 5 to generate the 2 nd drive pulse (P2 pulse).

For example, since the state of charge (state a) at time T3 and the state of charge (state B) at time T4 are different from each other during the period from time T3 to time T4 in fig. 9, pulse selection control unit 11 determines that state a and state B are different (step S208), and determines the output voltage of secondary battery 2 again (step S209). However, at this time, as shown by W2b in fig. 9, the pulse selection controller 11 determines that the 1 st determination result is equal to the 2 nd determination result because the output voltage of the secondary battery 2 does not change so as to cross the switching point CT between the time T3 and the time T4 (step S211). As a result, the pulse selection control unit 11 does not cause the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse).

Similarly, for example, in the period from time T7 to time T8 in fig. 9, since the state of charge (state a) at time T7 is different from the state of charge (state B) at time T8, pulse selection control unit 11 determines that state a is different from state B (step S208), and determines the output voltage of secondary battery 2 again (step S209). However, at this time, as shown in W4b of fig. 9, the pulse selection controller 11 determines that the 1 st determination result is equal to the 2 nd determination result because the output voltage of the secondary battery 2 does not change so as to cross the switching point CT between the time T7 and the time T8 (step S211). As a result, the pulse selection control unit 11 does not cause the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse).

Fig. 10 is a 4 th timing chart showing an example of the operation of the pulse selection control in the present embodiment. In the figure, the horizontal axis represents time and the vertical axis represents the power supply voltage, as in fig. 8 and 9. In addition, the figure shows the 1 st drive pulse (P1)_BPulse) is supplied to the motor 6 every 1 second.

Fig. 10 illustrates a process when the output voltage of the secondary battery 2 is lower than a predetermined switching point CT (for example, 1.5V) and does not cross the predetermined switching point CT before and after the output of the 1 st drive pulse, as shown in W1c to W5 c.

In W1c to W5c of fig. 10, since the output voltage of the secondary battery 2 is lower than the switching point CT, the pulse selection controller 11 causes the motor drive controller 5 to output (generate) P1_BThe pulse serves as the 1 st drive pulse. At this time, in the 1 st drive pulse (P1)_BPulse) before and after the output, the pulse selection control section 11 does not cause the motor drive control section 5 to generate the 2 nd drive pulse (P2 pulse) because the predetermined switching point CT is not crossed.

For example, since the state of charge (state a) at time T3 and the state of charge (state B) at time T4 are different from each other during the period from time T3 to time T4 in fig. 10, pulse selection control unit 11 determines that state a and state B are different (step S208), and determines the output voltage of secondary battery 2 again (step S209). However, at this time, as shown by W2c in fig. 10, the pulse selection controller 11 determines that the 1 st determination result is equal to the 2 nd determination result because the output voltage of the secondary battery 2 does not change so as to cross the switching point CT between the time T3 and the time T4 (step S211). As a result, the pulse selection control unit 11 does not cause the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse).

Similarly, for example, in the period from time T7 to time T8 in fig. 10, since the state of charge (state a) at time T7 is different from the state of charge (state B) at time T8, pulse selection control unit 11 determines that state a is different from state B (step S208), and determines the output voltage of secondary battery 2 again (step S209). However, at this time, as shown by W4c in fig. 10, the pulse selection controller 11 determines that the 1 st determination result is equal to the 2 nd determination result because the output voltage of the secondary battery 2 does not change so as to cross the switching point CT between the time T7 and the time T8 (step S211). As a result, the pulse selection control unit 11 does not cause the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse).

As described above, according to the present embodiment, the pulse selection control unit 11 changes the pulse width of the 1 st drive pulse in accordance with the output voltage of the secondary battery 2 detected by the battery voltage detection unit 8 and the predetermined switching point CT. When the state of charge before and after the output of the 1 st drive pulse is different and the output voltages of the secondary battery 2 before and after the output of the 1 st drive pulse cross the switching point CT, the pulse selection control unit 11 causes the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse). On the other hand, when the output voltage of the secondary battery 2 detected by the battery voltage detection unit 8 does not cross the predetermined switching point before and after the output of the 1 st drive pulse, the pulse selection control unit 11 does not cause the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse).

That is, in the case where the output voltage of the secondary battery 2 crosses the switching point CT before and after the 1 st drive pulse is output, the 1 st drive pulse may not be output in an appropriate pulse width. That is, at this time, a driving error may occur on the motor 6. Therefore, at this time, the pulse selection control unit 11 causes the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse). Thus, the timepiece 200 and the motor drive device 100 can reliably drive the motor 6 to rotate by the P2 pulse, and can correct a time error caused by the non-rotation of the motor. Therefore, in the timepiece 200 and the motor drive device 100, even when the state of charge of the secondary battery 2 (secondary power supply unit) changes during motor driving and the power supply voltage changes rapidly, the motor can be driven reliably.

When the output voltage of the secondary battery 2 does not cross the switching point CT before and after the 1 st drive pulse is output, the 1 st drive pulse is output with an appropriate pulse width because it is not necessary to change the pulse width of the 1 st drive pulse. Therefore, at this time, the pulse selection control unit 11 does not cause the motor drive control unit 5 to output (generate) the 2 nd drive pulse (P2 pulse). This makes it possible to suppress the occurrence of unnecessary P2 pulses and reduce the current consumption in the timepiece 200 and the motor drive device 100.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and modifications may be made without departing from the scope of the present invention. As an example, the following is shown.

In the above embodiment, the embodiment in which the solar cell 1 is used as the primary power supply unit has been described, but another embodiment in which a secondary power supply unit is used may be used. For example, a power generation device that converts kinetic energy into electric energy by electromagnetic induction may be used in the primary power supply unit.

In the above embodiment, the secondary battery 2 is used as the secondary power supply unit, but a capacitor may be used. In the above-described embodiment, the power supply line VDD is a VDD ground line representing the reference potential of the entire timepiece 200, but the power supply line VSS may be a VSS ground line representing the reference potential of the entire timepiece 200.

In the above embodiments, the charge detection backflow prevention unit 9 is disposed between the cathode terminal of the secondary battery 2 and the cathode terminal of the solar battery 1, but may be disposed between the anode terminal of the secondary battery 2 and the anode terminal of the solar battery 1. That is, the charge detection backflow prevention unit 9 may be configured to make the anode terminal of the secondary battery 2 and the anode terminal of the solar cell 1 non-conductive when the charge of the secondary battery 2 is to be stopped.

In the above-described embodiment, the oscillation control unit 3, the quartz resonator 4, the motor drive control unit 5, the battery voltage detection unit 8, the charge detection backflow prevention unit 9, the power consumption control unit 10, the pulse selection control unit 11, and the overcharge protection unit 12 in the timepiece 200 may be realized by dedicated hardware, may be configured by a memory and a cpu (central Processing unit), and may be realized by a program. In addition, the above-mentioned parts may be implemented by an integrated circuit (ic), etc.

In the above embodiment, the description has been given of the P1 of the 1 st drive pulse according to the voltage of the secondary battery 2_APulse sum P1_BThe two pulse widths of the pulses are switched, but not limited to this. For example, three or more pulse widths of the 1 st drive pulse may be switched according to the voltage of the secondary battery 2, or one pulse width of the 1 st drive pulse may be used.

In the above embodiment, the embodiment in which the power consumption control unit 10 includes the pulse selection control unit 11 has been described, but the invention is not limited thereto, and for example, the motor drive control unit 5 may include the pulse selection control unit 11. In addition, although the embodiment in which the motor drive control unit 5 outputs the pulse end signal to notify the pulse selection control unit 11 that the 1 st drive pulse has been output has been described, other embodiments are also possible. For example, it may be such that: when the timing at which the pulse selection control unit 11 outputs the drive pulse from the motor drive control unit 5 after outputting the pulse generation request signal is set in advance, the pulse end signal is not used.

The timepiece 200 described above includes a computer system therein. The procedure of the pulse selection control process is stored in a computer-readable storage medium in the form of a program, and the process is performed by reading the program and executing the program by a computer. Here, the computer-readable storage medium refers to a magnetic disk, an optical magnetic disk, a CD-ROM, a DVD-ROM, a semiconductor memory, or the like. In addition, the computer program may be distributed to a computer via a communication line, and the computer that has received the distribution executes the program.

While the embodiments of the present invention have been described above by taking a timepiece device as an example, the present invention is not limited to a timepiece device and can be effectively used in an electronic device including a solar battery (primary power supply unit), a secondary battery (secondary power supply unit), and a motor.

Claims (8)

1. A motor drive device characterized by comprising:

a charge detection unit that detects a charge state of a secondary power supply unit that is charged by electromotive force of a primary power supply unit, the charge state indicating whether or not the secondary power supply unit is being charged; and

and a control unit that generates a 1 st drive pulse for motor driving, and generates a 2 nd drive pulse for motor driving when the charging state detected by the charging detection unit is different before and after the 1 st drive pulse is output.

2. The motor drive device according to claim 1,

the 2 nd drive pulse is a drive pulse having a wider pulse width than the 1 st drive pulse.

3. The motor drive device according to claim 2,

the 2 nd drive pulse is a drive pulse having a pulse width of a sufficient degree or more necessary for rotating the motor.

4. The motor drive device according to claim 1,

the motor driving device has a battery voltage detecting section that detects an output voltage of the secondary power supply section,

the control unit changes the pulse width of the 1 st drive pulse according to the detection result of the battery voltage detection unit.

5. The motor drive device according to claim 4,

the control unit changes the pulse width of the 1 st drive pulse in accordance with the output voltage detected by the battery voltage detection unit and a predetermined switching point,

the control portion does not generate the 2 nd drive pulse in a case where the output voltage detected by the battery voltage detection portion does not cross the predetermined switching point before and after the 1 st drive pulse is output.

6. The motor drive device according to claim 1,

the primary power supply section is a solar cell.

7. Timepiece device, characterized in that it has a motor drive according to claim 1.

8. An electronic device characterized by having the motor drive apparatus of claim 1.