JP7105655B2 - electronic clock - Google Patents

Description

The present invention relates to electronic timepieces.

2. Description of the Related Art Conventionally, there is a technology for stopping hand movement in an electronic timepiece. Japanese Unexamined Patent Application Publication No. 2002-200000 discloses a technology of an electronic device in which a power saving mode for reducing power consumption and a display mode for normal time display are switched and set. The power saving mode of Patent Document 1 is an operation mode in which the driving of the stepping motor is stopped to stop the movement of the hands.

By the way, there is an electrostatic motor using an electrostatic actuator as a mechanism for driving hands in an electronic timepiece. An example of an electrostatic actuator is described, for example, in US Pat.

Japanese Patent No. 3484704 JP-A-4-112683

In an electronic timepiece, it is desirable to be able to maintain the stop position of the hands when the movement of the hands is stopped. On the other hand, it is desired that power consumption for maintaining the stop position of the hands can be suppressed. When a stepping motor such as that disclosed in Patent Document 1 is used, power consumption can be suppressed because a drive signal is not applied to the stepping motor while power consumption is being suppressed. However, when an electrostatic motor is installed in an electronic timepiece as a mechanism for driving the hands, the holding force with which the electrostatic motor tries to stay at that position becomes small unless a drive signal is applied as in Patent Document 1, and consumption is reduced. During power suppression, the position of the pointer is displaced due to a shock applied to the electronic timepiece.

SUMMARY OF THE INVENTION An object of the present invention is to provide an electronic timepiece capable of keeping hands stopped while suppressing power consumption.

An electronic timepiece according to the present invention comprises a power supply, a rotor having a plurality of electret films arranged along the direction of rotation, a plurality of fixed electrodes arranged along the direction of rotation at positions facing the rotor, a pointer that rotates in conjunction with the rotation of the rotor; and a motor control circuit that controls the electrostatic motor, wherein the motor control circuit controls a hand operation mode for rotating the pointer; and a stop mode in which the pointer is stopped, and in the stop mode, the motor control circuit acts on the electret film from the fixed electrode while maintaining the polarity of the fixed electrode. It is characterized in that the rotor is stopped by the electrostatic force applied.

An electronic timepiece according to the present invention includes a power source, a rotor having a plurality of electret films arranged along the direction of rotation, and a plurality of fixed electrodes arranged along the direction of rotation at positions facing the rotor. an electrostatic motor, pointers that rotate in conjunction with the rotation of the rotor, and a motor control circuit that controls the electrostatic motor.

A motor control circuit selectively executes a hand operation mode in which the hands are rotated and a stop mode in which the hands are stopped. In the stop mode, the motor control circuit keeps the rotor stopped by electrostatic forces acting on the electret film from the fixed electrodes while maintaining the polarity of the fixed electrodes. According to the electronic timepiece of the present invention, by stopping the rotor by the electrostatic force while maintaining the polarity of the fixed electrodes, it is possible to keep the hands stopped while suppressing power consumption. Play.

FIG. 1 is a front view of the electronic timepiece according to the first embodiment. FIG. 2 is a block diagram of the electronic timepiece according to the first embodiment. FIG. 3 is a schematic configuration diagram of the electrostatic motor according to the first embodiment. FIG. 4 is a schematic perspective view of the electrostatic motor according to the first embodiment. FIG. 5 is a diagram showing an example of hand movement control. FIG. 6 is a diagram of a booster circuit according to the first embodiment. FIG. 7 is a diagram showing the first state of the booster circuit. FIG. 8 is a diagram showing a second state of the booster circuit. FIG. 9 is a diagram for explaining the stop mode according to the first embodiment. FIG. 10 is a diagram for explaining power consumption in the booster circuit when the electrostatic motor operates. FIG. 11 is a time chart relating to the stop mode of the first embodiment. FIG. 12 is a flow chart showing the operation of the first embodiment. FIG. 13 is a schematic configuration diagram of an electrostatic motor according to the second embodiment. FIG. 14 is a schematic perspective view of an electrostatic motor according to the second embodiment. FIG. 15 is a diagram showing an example of hand movement control according to the second embodiment. FIG. 16 is a diagram showing the booster circuit of the second embodiment. FIG. 17 is a diagram for explaining the stop mode according to the second embodiment. FIG. 18 is a diagram showing another example of the stop mode according to the second embodiment. FIG. 19 is a diagram showing a booster circuit according to a first modification of the embodiment; FIG. 20 is a diagram for explaining the boosting operation in the booster circuit of the first modified example of the embodiment. FIG. 21 is a diagram showing a booster circuit according to a second modification of the embodiment;

An electronic timepiece according to an embodiment of the present invention will be described in detail below with reference to the drawings. In addition, this invention is not limited by this embodiment. In addition, components in the following embodiments include those that can be easily assumed by those skilled in the art or substantially the same components.

[First embodiment]
A first embodiment will be described with reference to FIGS. 1 to 12. FIG. This embodiment relates to an electronic timepiece. 1 is a front view of the electronic timepiece according to the first embodiment, FIG. 2 is a block diagram of the electronic timepiece according to the first embodiment, FIG. 3 is a schematic configuration diagram of the electrostatic motor according to the first embodiment, 4 is a schematic perspective view of an electrostatic motor according to the first embodiment, FIG. 5 is a diagram showing an example of hand movement control, FIG. 6 is a diagram of a booster circuit according to the first embodiment, and FIG. FIG. 8 is a diagram showing the first state of the circuit, FIG. 8 is a diagram showing the second state of the booster circuit, FIG. 9 is a diagram for explaining the stop mode according to the first embodiment, and FIG. 11 is a time chart relating to the stop mode of the first embodiment, and FIG. 12 is a flow chart showing the operation of the first embodiment.

The electronic timepiece 1 of this embodiment is an analog electronic timepiece that displays the time with a second hand 2, a minute hand 3, and an hour hand 4, as shown in FIG. The electronic timepiece 1 has an exterior case 31 , a dial 32 , a second hand 2 , a minute hand 3 , an hour hand 4 , and an operating section 18 . The electronic timepiece 1 of this embodiment is a wristwatch worn on a user's arm. The electronic timepiece 1 displays the current time with three hands (second hand 2, minute hand 3, and hour hand 4).

The dial 32 has scales 33 and hour characters 34 . A scale 33 is an index indicated by a pointer. The scales 33 are arranged on the outer edge of the dial 32 at predetermined intervals along the circumferential direction. The hour characters 34 are numbers indicating the time corresponding to each scale 33 . The operation unit 18 is an operation input unit operated by a user. The operation part 18 of this embodiment is a crown.

A power saving display 35 and a charging warning display 36 are provided on the exterior case 31 . The power saving display 35 is characters or symbols indicating that the electronic timepiece 1 is in the stop mode. As will be described later, the electronic timepiece 1 indicates to the user that the current mode is the stop mode by pointing the second hand 2 to the power saving display 35 . The power saving display 35 of this embodiment is arranged at the 12 o'clock position. As will be described later, the electronic timepiece 1 points the second hand 2 to the charging warning display 36 when in the charging warning state. The charge warning display 36 of this embodiment is arranged at the 4 o'clock position. Note that the power saving display 35 and the charging warning display 36 may be provided on the dial 32 .

As shown in FIG. 2, the electronic timepiece 1 further includes a train wheel 5, an electrostatic motor 11, an electromagnetic motor 12, an electrostatic motor drive circuit 13, a constant voltage source 14, a booster circuit 15, a power generation mechanism 16, a power source 17, and a control circuit 20 .

The train wheel 5 is interposed between the electrostatic motor 11 and the second hand 2 . The train wheel 5 is a deceleration train wheel having at least one gear, and transmits the rotational force generated by the electrostatic motor 11 to the second hand 2 . The train wheel 5 is arranged on the rear side with respect to the dial 32 . The train wheel 5 transmits the rotation of the rotating shaft of the electrostatic motor 11 to the second hand 2 after changing the speed at a predetermined reduction ratio.

The electrostatic motor 11 is an electret motor that uses an electret as an electrostatic material and rotates a rotor using electrostatic interaction between an electret film and a fixed electrode. Details of the configuration of the electrostatic motor 11 will be described later. The electrostatic motor drive circuit 13 is a circuit that controls the drive current for the electrostatic motor 11 .

The electromagnetic motor 12 is a motor using electromagnetic induction, such as a stepping motor. The electromagnetic motor 12 rotates the minute hand 3 and the hour hand 4 by intermittent driving that repeats a driving state and a temporary stop holding state. The electromagnetic motor 12 is connected to the minute hand 3 and the hour hand 4 via a deceleration train wheel, for example. An electromagnetic motor 12 moves the minute hand 3 and the hour hand 4 .

A power supply 17 supplies electric power for driving the electrostatic motor 11 and the electromagnetic motor 12 . The power source 17 of this embodiment is a secondary battery. The output voltage of the power supply 17 of this embodiment is a low voltage, for example, 2 to 3 [V]. A power generation mechanism 16 is connected to the power supply 17 . The power supply 17 is charged with electric power generated by the power generation mechanism 16 . The power generation mechanism 16 of this embodiment is an electrostatic induction type power generation mechanism. The power generation mechanism 16 converts the rotational energy of the rotor that rotates due to the movement of the arm on which the electronic timepiece 1 is worn, into electrical energy. Of course, a mechanism such as a solar power generation mechanism, an electromagnetic power generation mechanism, a thermal power generation mechanism, or an electrostatic induction power generation mechanism may be used as the power generation mechanism 16 .

The constant voltage source 14 is provided between the power source 17 and the booster circuit 15 . The constant voltage source 14 steps down the output voltage of the power source 17 to a predetermined voltage and supplies it to the booster circuit 15 . The constant voltage source 14 is configured to keep the input voltage of the booster circuit 15 constant even when the output voltage of the power source 17 fluctuates. The constant voltage source 14 may be omitted.

The booster circuit 15 boosts the voltage input from the constant voltage source 14 and supplies it to the electrostatic motor drive circuit 13 . The booster circuit 15 of this embodiment boosts the voltage by a predetermined magnification. Details of the booster circuit 15 will be described later. If the constant voltage source 14 is not provided, the voltage of the power source 17 fluctuates like a secondary battery. It does not matter if the boost ratio is switched.

The electrostatic motor drive circuit 13 is a circuit that drives the electrostatic motor 11 with power supplied through the booster circuit 15 . The electrostatic motor drive circuit 13 is interposed between the booster circuit 15 and the electrostatic motor 11 .

The control circuit 20 is a circuit that controls the electrostatic motor 11 , the electromagnetic motor 12 and the booster circuit 15 . In other words, the control circuit 20 of this embodiment has a function of a motor control circuit that controls the electrostatic motor 11 and a function of a voltage control circuit that controls the booster circuit 15 .

The electrostatic motor 11 has a rotor 40, a rotating shaft 41, and a stator 50, as shown in FIGS. The rotor 40 and the stator 50 of the present embodiment each have a disc shape, but the stator 50 is not limited to a disc shape, and may have a square shape or the like. The stator 50 of this embodiment is fixed to the housing or the like so as not to rotate. The rotating shaft 41 is fixed with respect to the rotor 40 . The rotating shaft 41 is rotatably supported by a housing or the like. The rotor 40 is coaxial with the stator 50 and faces the stator 50 with a gap therebetween.

The rotor 40 is a disk-shaped member formed of a substrate material such as a silicon substrate, a glass epoxy substrate provided with an electrode surface for charging, or an aluminum plate. A plurality of electret films 42 are formed on the surface of the rotor 40 facing the stator 50 . The electret films 42 are arranged at regular intervals along the direction of rotation about the rotation shaft 41 . The electret film 42 is a thin film made of an electret material. The electret film 42 of this embodiment is charged to a negative potential. Through holes 43 are formed between adjacent electret films 42 in the rotor 40 .

A plurality of fixed electrodes 51 , 52 , 53 are arranged on the surface of the stator 50 facing the rotor 40 . The electrostatic motor 11 of this embodiment is a three-phase motor of U-phase, V-phase, and W-phase. The fixed electrode 51 is an electrode corresponding to the U phase, and will be referred to as a "first electrode 51" in the following description. The fixed electrode 52 is an electrode corresponding to the V phase, and will be referred to as a "second electrode 52" in the following description. The fixed electrode 53 is an electrode corresponding to the W phase, and will be referred to as a "third electrode 53" in the following description. The first electrodes 51 , the second electrodes 52 , and the third electrodes 53 are arranged at regular intervals along the rotation direction of the rotor 40 .

A plurality of electrode groups 54 each including a first electrode 51 , a second electrode 52 and a third electrode 53 are arranged on the stator 50 . The multiple electrode groups 54 are arranged at equal intervals along the rotation direction of the rotor 40 .

Each first electrode 51 is electrically connected to the electrostatic motor drive circuit 13 via a common first wiring. That is, a common driving pulse is input to each first electrode 51 . Similarly, each second electrode 52 is electrically connected to the electrostatic motor drive circuit 13 through a common second wiring, and each third electrode 53 is electrostatically connected through a common third wiring. It is electrically connected to the motor drive circuit 13 . Therefore, a common driving pulse is input from the electrostatic motor driving circuit 13 to each second electrode 52 , and a common driving pulse is input from the electrostatic motor driving circuit 13 to each third electrode 53 .

Each electrode 51, 52, 53 generates an attractive force or a repulsive force with the electret film 42 according to the polarity generated by the drive pulse. The electrostatic motor drive circuit 13 rotates the rotor 40 or stops the rotor 40 by electrostatic forces acting on the electret film 42 from the electrodes 51 , 52 , 53 .

FIG. 5 shows an example of control for rotationally driving the rotor. In the state shown in (a) of FIG. 5 , the central portion 42 a of the electret film 42 faces the first electrode 51 . In this case, the electrostatic motor drive circuit 13 uses the first electrode 51 as a negative electrode and the second electrode 52 and the third electrode 53 as positive electrodes. Thereby, the first electrode 51 causes electrostatic repulsion to act on the electret film 42 , and the second electrode 52 and the third electrode 53 cause electrostatic attraction to act on the electret film 42 . Electrostatic attraction acts from the second electrode 52 and the third electrode 53 positioned forward in the rotation direction CW, and thus a rotational force is applied to the electret film 42 in the rotation direction CW. In addition, the electrostatic repulsive force acts from the first electrode 51 located behind in the rotation direction CW, so that a rotation force in the rotation direction CW is applied to the electret film 42 .

In the state shown in (b) of FIG. 5 , the central portion 42 a of the electret film 42 faces the second electrode 52 . In this case, the electrostatic motor drive circuit 13 uses the second electrode 52 as a negative electrode and the first electrode 51 and the third electrode 53 as positive electrodes. Due to the electrostatic attraction acting on the electret film 42 from the first electrode 51 and the third electrode 53 and the electrostatic repulsion acting on the electret film 42 from the second electrode 52, the electret film 42 rotates in the direction of rotation. A rotational force is applied toward CW.

In the state shown in (c) of FIG. 5 , the central portion 42 a of the electret film 42 faces the third electrode 53 . In this case, the electrostatic motor drive circuit 13 uses the third electrode 53 as a negative electrode and the first electrode 51 and the second electrode 52 as positive electrodes. Due to the electrostatic attraction acting on the electret film 42 from the first electrode 51 and the second electrode 52 and the electrostatic repulsion acting on the electret film 42 from the third electrode 53, the electret film 42 is rotated in the direction of rotation. A rotational force is applied toward CW. The electrostatic motor drive circuit 13 rotates the rotor 40 by sequentially switching the polarities of the first electrode 51 , the second electrode 52 , and the third electrode 53 according to the rotational position of the electret film 42 .

As shown in FIG. 6, the booster circuit 15 has a first capacitor 21, a second capacitor 22, a third capacitor 23, a fourth capacitor 24, a first switch 25, and a second switch . As described below, the booster circuit 15 alternately connects the first capacitor 21, the second capacitor 22, and the third capacitor 23 to the constant voltage source 14 in parallel or in series, thereby increasing the voltage of the constant voltage source 14. is boosted and stored in the fourth capacitor 24 .

The first switch 25 and the second switch 26 are switching elements such as MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors). The booster circuit 15 has six switches 25 a, 25 b, 25 c, 25 d, 25 e, and 25 f as the first switch 25 . The switch 25 a connects and disconnects the constant voltage source 14 and the first electrode 21 a of the first capacitor 21 . The switch 25 b connects and disconnects the constant voltage source 14 and the first electrode 22 a of the second capacitor 22 . The switch 25 c connects and disconnects the constant voltage source 14 and the first electrode 23 a of the third capacitor 23 . The switch 25 d connects and disconnects the second electrode 21 b of the first capacitor 21 and the second electrode 24 b of the fourth capacitor 24 . The switch 25 e connects and disconnects the second electrode 22 b of the second capacitor 22 and the second electrode 24 b of the fourth capacitor 24 . The switch 25f connects and disconnects the second electrode 23b of the third capacitor 23 and the second electrode 24b of the fourth capacitor 24. As shown in FIG.

The booster circuit 15 has four switches 26 a , 26 b , 26 c and 26 d as the second switch 26 . The switch 26a connects and disconnects the constant voltage source 14 with the second electrode 21b of the first capacitor 21 and the second electrode 24b of the fourth capacitor 24. FIG. The switch 26b connects and disconnects the first electrode 21a of the first capacitor 21 and the second electrode 22b of the second capacitor 22 . The switch 26 c connects and disconnects the first electrode 22 a of the second capacitor 22 and the second electrode 23 b of the third capacitor 23 . The switch 26 d connects and disconnects the first electrode 23 a of the third capacitor 23 and the first electrode 24 a of the fourth capacitor 24 . A first electrode 24 a of the fourth capacitor 24 is connected to the input of the electrostatic motor drive circuit 13 .

By turning on the first switch 25 and turning off the second switch 26, the booster circuit 15 becomes a circuit equivalent to the circuit shown in FIG. As shown in FIG. 7, the first capacitor 21, the second capacitor 22, and the third capacitor 23 are connected in parallel to the constant voltage source 14, respectively. Therefore, the three capacitors 21 , 22 , 23 are charged with the output voltage of the constant voltage source 14 .

On the other hand, by turning off the first switch 25 and turning on the second switch 26, the booster circuit 15 becomes a circuit equivalent to the circuit shown in FIG. As shown in FIG. 8, the first capacitor 21, the second capacitor 22, and the third capacitor 23 are connected in series with the constant voltage source . A fourth capacitor 24 is connected in parallel with the constant voltage source 14 and the three capacitors 21 , 22 , 23 and is charged by the constant voltage source 14 and the three capacitors 21 , 22 , 23 . That is, the voltage of the constant voltage source 14 is quadrupled and stored in the fourth capacitor 24 . Also, the voltage boosted by the booster circuit 15 is supplied to the electrostatic motor drive circuit 13 .

The control circuit 20 outputs a signal for controlling the first switch 25 and a signal for controlling the second switch 26, respectively. The control circuit 20 also generates and outputs various clock signals for controlling the electronic timepiece 1 . The control circuit 20 alternately outputs a first control signal for setting the booster circuit to the state shown in FIG. 7 and a second control signal for setting the booster circuit 15 to the state shown in FIG. The booster circuit 15 alternately repeats the state shown in FIG. 7 and the state shown in FIG.

The control circuit 20 of this embodiment selectively executes the hand operation mode and the stop mode. The hand movement mode is a control mode for rotating the second hand 2 . The hand operation mode is a normal mode in which the second hand 2, minute hand 3, and hour hand 4 are all operated. In the hand movement mode, the control circuit 20 moves the minute hand 3 and the hour hand 4 by the electromagnetic motor 12 and moves the second hand 2 by the electrostatic motor 11 . That is, in the hand movement mode, the second hand 2, minute hand 3, and hour hand 4 all point to the position corresponding to the current time. In the hand movement mode, the control circuit 20 rotates the electrostatic motor 11 to rotate the second hand 2 continuously as described with reference to FIG.

The stop mode is a control mode in which the second hand 2 is stopped. The stop mode is a power saving mode in which the minute hand 3 and hour hand 4 are moved while the second hand 2 is stopped. In the stop mode, the control circuit 20 moves the minute hand 3 and the hour hand 4 by the electromagnetic motor 12 and stops the second hand 2 by the electrostatic motor 11 . As described below, the control circuit 20 of the present embodiment stops the rotor 40 of the electrostatic motor 11 while maintaining the polarities of the fixed electrodes 51, 52, 53 in the stop mode. The electronic timepiece 1 of this embodiment can reduce power consumption while maintaining the pointer position of the second hand 2 by not switching the polarities of the fixed electrodes 51, 52, and 53 in the stop mode.

The operation of the electrostatic motor 11 in the stop mode will be described with reference to FIG. In the stop mode, the control circuit 20 applies an electrostatic attractive force F1 to the electret film 42 by the counter electrode. Here, the counter electrode is an electrode among the plurality of fixed electrodes 51 , 52 , 53 that faces the central portion 42 a of the electret film 42 . In FIG. 9 , the third electrode 53 faces the central portion 42 a of the electret film 42 . In this case, the third electrode 53 becomes the counter electrode.

In stop mode, the control circuit 20 makes the counter electrode the positive electrode. That is, the control circuit 20 makes the polarity of the counter electrode opposite to the polarity of the electret film 42 . In FIG. 9, the third electrode 53, which is the counter electrode, is a positive positive electrode. The third electrode 53 applies an electrostatic attractive force F<b>1 to the electret film 42 . The electrostatic attraction F<b>1 acts to maintain the electret film 42 at a position facing the third electrode 53 . That is, when the rotor 40 tries to rotate so that the electret film 42 moves away from the third electrode 53, the movement is restricted by the electrostatic attraction F1.

In the stop mode, the control circuit 20 causes electrostatic repulsion to act on the electret film 42 by adjacent electrodes. Here, the adjacent electrode is an electrode among the plurality of fixed electrodes 51, 52, 53 that is adjacent to the counter electrode. In FIG. 9, the first electrode 51 and the second electrode 52 are adjacent electrodes.

In stop mode, the control circuit 20 makes the adjacent electrode negative. In FIG. 9, the first electrode 51 and the second electrode 52, which are adjacent electrodes, are each negatively charged. The first electrode 51 and the second electrode 52 each apply an electrostatic repulsive force F2 to the electret film 42 . The electrostatic repulsive force F2 generated by the second electrode 52 is a repulsive force directed in the rotation direction CW. On the other hand, the electrostatic repulsive force F2 generated by the first electrode 51 is a repulsive force directed in a direction opposite to the rotation direction CW. Therefore, the electrostatic repulsive force F2 acts to maintain the rotational position of the electret film 42 at the position facing the third electrode 53 . That is, when the rotor 40 tries to rotate so that the electret film 42 moves away from the third electrode 53, the movement is restricted by the electrostatic repulsive force F2. Electrostatic attraction F1 and electrostatic repulsion F2 act on the electret films 42 of the rotor 40, which generates a holding force and prevents the hands from being displaced due to impacts applied to the electronic timepiece 1 in the stop mode.

In the stop mode, the control circuit 20 maintains the polarity of the counter electrode (here, the third electrode 53) to be positive and the polarity of the adjacent electrodes (here, the first electrode 51 and the second electrode 52) to be negative. maintain. Power consumption in the electrostatic motor 11 is reduced because the polarities of the fixed electrodes 51, 52, and 53 are not switched.

FIG. 10 is a diagram for explaining power consumption in the booster circuit when the electrostatic motor operates. Power consumption due to switching of the polarities of the fixed electrodes 51, 52, 53 will be described with reference to FIG. FIG. 10 shows the boost clock signal SW, boost voltage VW, and current waveform IW. The boost clock signal SW is a switching signal for the boost operation in the boost circuit 15 . The above-described first control signal and second control signal are switched according to on/off of the boost clock signal SW.

The boosted voltage VW is a voltage supplied to the electrostatic motor drive circuit 13 . A current waveform IW is a current value flowing through the booster circuit 15 . A large current instantaneously flows each time the boost clock signal SW is switched between on and off, and the current waveform IW rises in a spike shape. In FIG. 10, the polarities of the fixed electrodes 51, 52, 53 are switched at time t1. As the polarity is switched, the boosted voltage VW temporarily drops due to parasitic capacitance and the like. As a result, the power consumption in the booster circuit 15 increases because it is necessary to flow a current in order to restore the lowered boosted voltage VW.

By switching the clock operation according to the boost clock signal SW, power is consumed by the through current of the level shifter and the charge/discharge current of the gates of the drivers in the switches 25 and 26 . That is, the clock operation increases the power consumption in the booster circuit 15 . Power consumption in booster circuit 15 depends on boosted clock signal SW and boosted voltage VW. For example, the power consumption increases as the frequency of the boost clock signal SW increases, and the power consumption increases as the boost voltage VW increases.

In the electronic timepiece 1 of this embodiment, the polarities of the fixed electrodes 51, 52, 53 are not switched in the stop mode. Therefore, the electronic timepiece of this embodiment can reduce power consumption in the stop mode. FIG. 11 shows the boost clock signal SW2, boost voltage VW2, and current waveform IW2 in the stop mode. Since the polarities of the fixed electrodes 51, 52, and 53 are not switched, the boosted voltage VW2 does not fluctuate as shown in FIG.

Furthermore, the control circuit 20 of the present embodiment performs control to reduce the power consumption of the booster circuit 15 in the stop mode as compared to the power consumption of the booster circuit 15 in the hand operation mode. As a specific example, the control circuit 20 of this embodiment makes the number of clocks of the booster circuit 15 in the stop mode lower than the number of clocks in the hand movement mode. The number of clocks N of the booster circuit 15 is, for example, the number of pulses of the booster clock signal SW per unit time. In FIG. 11, for comparison, the boosted clock signal SW1 in the hand movement mode is indicated by a dashed line.

Here, the number of clocks N in the hand movement mode is called the first number of clocks N1, and the number of clocks N in the stop mode is called the second number of clocks N2. In this embodiment, the number of clocks N is set as shown in Equation (1) below. That is, the second clock number N2 is smaller than the first clock number N1. The second clock number N2 may be, for example, half the first clock number N1.
N1>N2 (1)

Since the second clock number N2 is smaller than the first clock number N1, the power consumption of the booster circuit 15 in the stop mode is reduced. For example, the spikes of the current waveform IW that occur per unit time are reduced. Therefore, the electronic timepiece 1 of this embodiment can achieve both reduction in power consumption and holding of the stop position of the second hand 2 .

The electronic timepiece 1 of this embodiment switches control modes, for example, as described with reference to FIG. The control flow shown in FIG. 12 is, for example, repeatedly executed at predetermined intervals. At step S10, the control circuit 20 sets the control mode of the electronic timepiece 1 to the hand operation mode. After step S10 is executed, the process proceeds to step S20.

In step S20, the control circuit 20 determines whether or not no power generation has continued for 30 minutes or more. If the power generation mechanism 16 has not generated power for 30 minutes or longer, an affirmative determination is made in step S20, and the process proceeds to step S30. On the other hand, if a negative determination is made in step S20, the process proceeds to step S10.

At step S30, the control circuit 20 sets the control mode of the electronic timepiece 1 to the stop mode. The control circuit 20 stops the second hand 2 by the electrostatic motor 11 . The control circuit 20 of this embodiment stops the second hand 2 at a predetermined stop position. The stop position of the second hand 2 is the position pointing to the power saving display 35 . Therefore, when the stop mode is set, the control circuit 20 moves the second hand 2 to the position pointing to the power saving display 35 and stops the second hand 2 at the position pointing to the power saving display 35 .

The condition for returning from the stop mode to the hand operation mode is that power generation by the power generation mechanism 16 is detected. For example, when power generation by the power generation mechanism 16 is detected and the cumulative time of power generation by the power generation mechanism 16 reaches a predetermined judgment value, the control circuit 20 drives the electrostatic motor 11 to set the second hand 2 to correspond to the internal time. By rotating it to the position, the control mode of the electronic timepiece 1 is switched to the hand movement mode. The internal time is the time acquired from the current time holding unit that holds the current time in the control circuit 20 .

As described above, the electronic timepiece 1 of this embodiment has the power supply 17 , the electrostatic motor 11 , the second hand 2 , and the control circuit 20 . The electrostatic motor 11 has a rotor 40 and a plurality of fixed electrodes 51 , 52 , 53 . A plurality of electret films 42 are arranged on the rotor 40 along the direction of rotation. A plurality of fixed electrodes 51 , 52 , 53 are arranged along the rotation direction of rotor 40 at positions facing rotor 40 . The control circuit 20 is configured to function as a motor control circuit that controls the electrostatic motor 11 .

The control circuit 20 selectively executes a hand operation mode in which the second hand 2 is rotated and a stop mode in which the second hand 2 is stopped. In the stop mode, the control circuit 20 stops the rotor 40 by electrostatic force acting on the electret film 42 from the fixed electrodes 51, 52, 53 while maintaining the polarities of the fixed electrodes 51, 52, 53. back. In the electronic timepiece 1 of the present embodiment, by maintaining the polarities of the fixed electrodes 51, 52, and 53 in the stop mode, the second hand 2 can be stopped while suppressing power consumption.

In the stop mode, the control circuit 20 of the present embodiment applies electrostatic attraction to the electret film 42 by means of the counter electrode. The counter electrodes are fixed electrodes 51 , 52 , 53 facing the central portion 42 a of the electret film 42 . The central portion 42a is, for example, the central portion of the electret film 42 in the rotation direction CW. Appropriate holding force for stopping the second hand 2 can be generated by applying an electrostatic attractive force to the electret film 42 by the counter electrode.

In the stop mode, the control circuit 20 of the present embodiment causes electrostatic repulsion to act on the electret film 42 by adjacent electrodes. Adjacent electrodes are the fixed electrodes 51, 52, 53 adjacent to the counter electrode. The rotation of the second hand 2 can be restricted by the electrostatic repulsive force exerted by the adjacent electrodes.

The electronic timepiece 1 of this embodiment further includes a booster circuit 15 and a voltage control circuit. The booster circuit 15 is a circuit that boosts the voltage of the power supply 17 and supplies it to the electrostatic motor 11 . The control circuit 20 is configured to function as a voltage control circuit. The control circuit 20 reduces the power consumption of the booster circuit 15 in the stop mode as compared to the power consumption in the hand operation mode. By reducing the power consumption of the booster circuit 15, the second hand 2 can be stopped while suppressing the power consumption.

The control circuit 20 of the present embodiment makes the number of clocks of the booster circuit 15 in the stop mode (second number of clocks N2) smaller than the number of clocks of the booster circuit 15 in the movement mode (first number of clocks N1). This reduces power consumption in the stop mode.

The electrostatic motor 11 of the present embodiment may have fixed electrodes on both sides of the rotor 40 in the axial direction. In this case, the second stator is arranged on the side opposite to the stator 50 with respect to the rotor 40 . U-phase, V-phase, and W-phase stationary electrodes are arranged on the second stator. In the stop mode, among the fixed electrodes arranged on the second stator, the opposing electrode is the anode and the adjacent electrode is the cathode.

[Second embodiment]
A second embodiment will be described with reference to FIGS. 13 to 18. FIG. In the second embodiment, constituent elements having functions similar to those described in the first embodiment are denoted by the same reference numerals, and overlapping descriptions are omitted. 13 is a schematic configuration diagram of the electrostatic motor according to the second embodiment, FIG. 14 is a schematic perspective view of the electrostatic motor according to the second embodiment, and FIG. 15 shows an example of hand movement control of the second embodiment. 16 is a diagram showing the booster circuit of the second embodiment; FIG. 17 is a diagram for explaining the stop mode according to the second embodiment; FIG. 18 is another diagram of the stop mode according to the second embodiment; FIG. 4 is a diagram showing an example;

As shown in FIGS. 13 and 14, the electrostatic motor 11 according to the second embodiment has a rotor 40, a rotating shaft 41, a first stator 60A and a second stator 60B. The shape of the first stator 60A and the second stator 60B is disc-shaped, but the stator 50 is not limited to the disc-shape, and may be square or the like. The first stator 60A and the second stator 60B of this embodiment face each other with the rotor 40 interposed therebetween. That is, the first stator 60A faces one side of the rotor 40, and the second stator 60B faces the other side of the rotor 40. As shown in FIG. The rotor 40 is arranged coaxially with the first stator 60A and the second stator 60B with a gap therebetween.

The electrostatic motor 11 of this embodiment is a two-phase motor. A first electrode 61 and a second electrode 62 as fixed electrodes are arranged on a surface of the first stator 60A facing the rotor 40 . The first electrodes 61 and the second electrodes 62 are alternately arranged along the rotation direction of the rotor 40 . A third electrode 63 and a fourth electrode 64 as fixed electrodes are arranged on the surface of the second stator 60B facing the rotor 40 . The third electrodes 63 and the fourth electrodes 64 are alternately arranged along the rotation direction of the rotor 40 . The third electrode 63 and the fourth electrode 64 are out of rotational phase with both the first electrode 61 and the second electrode 62 . Specifically, the electrode pair consisting of the adjacent third electrode 63 and fourth electrode 64 is arranged with a shift of 1/4 period with respect to the electrode pair consisting of the adjacent first electrode 61 and second electrode 62. .

Each first electrode 61 is electrically connected to the electrostatic motor drive circuit 13 via a common first wiring. Each second electrode 62 is electrically connected to the electrostatic motor drive circuit 13 via a common second wiring. Each third electrode 63 is electrically connected to the electrostatic motor drive circuit 13 via a common third wiring. Each fourth electrode 64 is electrically connected to the electrostatic motor drive circuit 13 via a common fourth wiring.

FIG. 15 shows an example of control for driving the rotor 40 to rotate. In the state shown in FIG. 15( a ), the third electrode 63 faces the central portion 42 a of the electret film 42 . The first electrode 61 and the fourth electrode 64 are positioned forward of the electret film 42 in the rotational direction CW, and the second electrode 62 is positioned rearward in the rotational direction CW. In this case, the control circuit 20 sets the second electrode 62 and the third electrode 63 as negative electrodes, and sets the first electrode 61 and the fourth electrode 64 as positive electrodes. The second electrode 62 exerts an electrostatic repulsive force on the electret film 42 in the direction of rotation CW. The first electrode 61 and the fourth electrode 64 apply electrostatic attraction to the electret film 42 in the rotational direction CW.

In the state shown in (b) of FIG. 15 , the first electrode 61 faces the central portion 42 a of the electret film 42 . The second electrode 62 and the fourth electrode 64 are positioned forward of the electret film 42 in the rotational direction CW, and the third electrode 63 is positioned rearward of the electret film 42 in the rotational direction CW. In this case, the control circuit 20 sets the first electrode 61 and the third electrode 63 as negative electrodes, and sets the second electrode 62 and the fourth electrode 64 as positive electrodes. As a result, an electrostatic force acts on the electret film 42 in the direction of rotation CW.

In the state shown in (c) of FIG. 15 , the fourth electrode 64 faces the central portion 42 a of the electret film 42 . The second electrode 62 and the third electrode 63 are located forward of the electret film 42 in the rotational direction CW, and the first electrode 61 is located rearward of the electret film 42 in the rotational direction CW. In this case, the control circuit 20 sets the first electrode 61 and the fourth electrode 64 as negative electrodes and the second electrode 62 and the third electrode 63 as positive electrodes. As a result, an electrostatic force acts on the electret film 42 in the direction of rotation CW.

In the state shown in (d) of FIG. 15 , the second electrode 62 faces the central portion 42 a of the electret film 42 . The first electrode 61 and the third electrode 63 are positioned forward of the electret film 42 in the rotational direction CW, and the fourth electrode 64 is positioned rearward in the rotational direction CW. In this case, the control circuit 20 uses the second electrode 62 and the fourth electrode 64 as negative electrodes, and the first electrode 61 and the third electrode 63 as positive electrodes. As a result, an electrostatic force acts on the electret film 42 in the direction of rotation CW.

As described above, the control circuit 20 sequentially switches the polarities of the first electrode 61 , the second electrode 62 , the third electrode 63 , and the fourth electrode 64 , thereby imparting rotational force to the rotor 40 . In the electrostatic motor 11 of this embodiment, the first stator 60A and the second stator 60B each have two-phase electrodes, and are substantially controlled as a four-phase motor.

FIG. 16 is a diagram showing the booster circuit of the second embodiment. The booster circuit 15 of the second embodiment differs from the booster circuit 15 (FIG. 6) of the first embodiment in that a third switch 27 is provided between the power supply 17 and the electrostatic motor drive circuit 13. It is a point. When the third switch 27 is turned on, the power supply 17 is connected to the input portion of the electrostatic motor drive circuit 13 without going through the constant voltage source 14 and the booster circuit 15 . In this case, the output voltage of the power supply 17 becomes the input voltage to the electrostatic motor drive circuit 13 .

The operation of the electrostatic motor 11 in the stop mode of the second embodiment will be described with reference to FIG. In the stop mode, the control circuit 20 applies electrostatic attraction to the electret film 42 by the counter electrode. In the state shown in FIG. 17, the first electrode 61 and the third electrode 63 are opposed to the central portion 42a of the electret film 42. As shown in FIG. The fourth electrode 64 is positioned ahead of the central portion 42a of the electret film 42 in the rotational direction CW. The second electrode 62 is located behind the central portion 42a of the electret film 42 in the rotational direction CW. That is, the first electrode 61 and the third electrode 63 are opposing electrodes, and the second electrode 62 and the fourth electrode 64 are adjacent electrodes.

In this state, the control circuit 20 sets the first electrode 61 and the third electrode 63 as positive electrodes, and sets the second electrode 62 and the fourth electrode 64 as negative electrodes. The first electrode 61 and the third electrode 63 apply electrostatic attraction to the electret film 42 . Note that there is a phase difference between the phase of the first electrode 61 and the phase of the third electrode 63 . Therefore, the first electrode 61 applies an electrostatic attractive force F11 toward the rotation direction CW to the electret film 42 . On the other hand, the third electrode 63 applies an electrostatic attractive force F12 to the electret film 42 in a direction opposite to the rotation direction CW. These electrostatic attractive forces F11 and F12 cancel each other in the rotational direction CW. That is, the rotor 40 stops at a position where the electrostatic attractive forces F11 and F12 are balanced.

The second electrode 62 applies an electrostatic repulsive force F21 in the rotation direction CW to the electret film 42 . On the other hand, the fourth electrode 64 applies an electrostatic repulsive force F22 to the electret film 42 in a direction opposite to the rotation direction CW. These electrostatic repulsive forces F21 and F22 cancel each other out. That is, the rotor 40 stops at a position where the electrostatic repulsive forces F21 and F22 are balanced.

In the stop mode, the control circuit 20 of the present embodiment stops boosting by the booster circuit 15 and supplies the voltage of the power supply 17 to the electrostatic motor 11 . In the stop mode, the control circuit 20 stops boosting by the booster circuit 15 and turns on the third switch 27 . The power supply 17 and the electrostatic motor drive circuit 13 are connected via the third switch 27 . Thereby, the voltage of the power supply 17 is supplied to the electrostatic motor drive circuit 13 . When stopping the boosting by the booster circuit 15 , the control circuit 20 may turn off the first switch 25 and the second switch 26 .

Power consumption in the booster circuit 15 is reduced by stopping boosting by the booster circuit 15 . Therefore, the electronic timepiece 1 of the present embodiment can reduce power consumption while maintaining the pointer position of the second hand 2 in the stop mode.

Note that the control circuit 20 may supply a voltage lower than the voltage of the power supply 17 to the electrostatic motor 11 in the stop mode. For example, in stop mode, the output voltage of constant voltage source 14 may be supplied to electrostatic motor drive circuit 13 . In this case, for example, the first switch 25 c and the second switch 26 d are arranged to connect the constant voltage source 14 and the electrostatic motor drive circuit 13 .

In the stop mode shown in FIG. 17, the rotor 40 is stopped at the position where the electrostatic attractive forces F11 and F12 are balanced, but the rotor 40 may be stopped by the electrostatic forces shown in FIG. In the stop mode shown in FIG. 18, the third electrode 63 exerts an electrostatic attractive force F13 on the electret film 42, and the first electrode 61, the second electrode 62, and the fourth electrode 64 are static on the electret film 42. Electro-repulsive forces F23, F24, F25 and F26 are applied. More specifically, the first electrode 61 applies an electrostatic repulsive force F23 to the electret film 42 in a direction opposite to the rotation direction CW. The second electrode 62 acts on the electret film 42 with an electrostatic repulsive force F24 in the rotational direction CW. The fourth electrode 64 acts on the electret film 42 with an electrostatic repulsive force F25 in the rotational direction CW and an electrostatic repulsive force F26 in a direction opposite to the rotational direction CW. The rotor 40 stops at a position where two electrostatic repulsive forces F24 and F25 in the rotational direction CW and two electrostatic repulsive forces F23 and F26 in opposite directions are balanced.

As described above, the control circuit 20 according to the second embodiment stops boosting by the booster circuit 15 in the stop mode, and supplies a voltage equal to or lower than the voltage of the power supply 17 to the electrostatic motor 11, thereby 40, the power consumption of the booster circuit 15 is reduced in the stop mode while applying electrostatic attraction F11, F12, F13 and electrostatic repulsion F21, F22, F23, F24, F25, F26.

[First modification of the embodiment]
A first modification of the first and second embodiments will be described. FIG. 19 is a diagram showing a booster circuit according to the first modification of the embodiment, and FIG. 20 is a diagram explaining the boosting operation in the booster circuit of the first modification of the embodiment. The booster circuit 15 according to the first modification of the embodiment differs from the booster circuit 15 of the first embodiment in that it has a fourth switch 28 and a fifth switch 29 .

The booster circuit 15 has two switches 28 a and 28 b as the fourth switch 28 . The switch 28 a is a switch that connects and disconnects the output of the constant voltage source 14 and the first electrode 21 a of the first capacitor 21 . The switch 28b is a switch that connects and disconnects the second electrode 21b of the first capacitor 21 and the second electrode 24b of the fourth capacitor 24 . The fifth switch 29 is a switch that connects and disconnects the switch 26 a and the second electrode 21 b of the first capacitor 21 . In the hand movement mode, the fourth switch 28 is turned off and the fifth switch 29 is turned on. In this case, by turning on the first switch 25 and turning off the second switch 26, the booster circuit 15 becomes a circuit equivalent to the circuit shown in FIG. By turning off the first switch 25 and turning on the second switch 26, the booster circuit 15 becomes a circuit equivalent to the circuit shown in FIG.

On the other hand, in the stop mode, the fourth switch 28 is turned on and the fifth switch 29 is turned off. In this case, by turning on the first switch 25 and turning off the second switch 26, the booster circuit 15 becomes a circuit equivalent to the circuit shown in FIG. By turning off the first switch 25 and turning on the second switch 26, the booster circuit 15 becomes a circuit equivalent to the circuit shown in FIG. In the circuit shown in FIG. 20 , the second capacitor 22 and the third capacitor 23 are connected in series with the constant voltage source 14 . The first capacitor 21 is connected in parallel with the constant voltage source 14 . Therefore, the voltage of the constant voltage source 14 is tripled and stored in the fourth capacitor 24 . That is, depending on whether the fourth switch 28 and the fifth switch 29 are turned on/off, the boosting factor in the boosting circuit 15 is switched to triple or quadruple.

The control circuit 20 of this modification sets the boosting factor of the boosting circuit 15 to four times in the hand movement mode, and sets the boosting factor of the booster circuit 15 to three times in the stop mode. That is, the control circuit 20 makes the boosting factor of the boosting circuit 15 in the stop mode lower than the boosting factor of the booster circuit 15 in the hand operation mode. Since the through current also decreases in proportion to the voltage by lowering the boost factor in the stop mode, the power consumption of the booster circuit 15 in the stop mode is reduced.

Note that the ratio between the boost factor in the hand movement mode and the boost factor in the stop mode is not limited to the illustrated ratio. For example, the boost factor in the stop mode may be half or one third of the boost factor in the hand movement mode.

[Second Modification of Embodiment]
A second modification of the first and second embodiments will be described. FIG. 21 is a diagram showing a booster circuit according to a second modification of the embodiment; In the booster circuit 15 of the second modified example, the capacitor in which the boosted voltage is stored can be switched. The booster circuit 15 of the second modification has two capacitors 241 and 242 as the fourth capacitor 24 . Two capacitors 241 and 242 are connected in parallel. The capacity of one capacitor 241 is larger than the capacity of the other capacitor 242 . The booster circuit 15 has a sixth switch 30A and a seventh switch 30B. The sixth switch 30A connects and disconnects the first electrode 24a of one capacitor 241, the switch 26d and the electrostatic motor drive circuit 13. FIG. The seventh switch 30B connects and disconnects the first electrode 24a of the other capacitor 242 with the switch 26d and the electrostatic motor drive circuit 13. FIG. The booster circuit 15 turns on the sixth switch 30A and turns off the seventh switch 30B in the hand movement mode. As a result, the boosted voltage is stored in one capacitor 241 . In the stop mode, the booster circuit 15 turns off the sixth switch 30A and turns on the seventh switch 30B. As a result, the boosted voltage is stored in the other capacitor 242 .

By accumulating the boosted voltage in the small-capacity capacitor 242 in the stop mode, the loss due to charge leakage or the like is reduced. Therefore, the booster circuit 15 of the second modification can reduce power consumption in the stop mode.

[Third modification of the embodiment]
A third modification of the first and second embodiments will be described. The electret film 42 may be charged to a positive potential. In this case, in stop mode, the counter electrode is the negative electrode and the adjacent electrode is the positive electrode.

Note that the combination of the polarities of the opposing electrodes and the polarities of the adjacent electrodes is not limited to the exemplified combinations. That is, the polarities and potential magnitudes of the opposing electrodes and the adjacent electrodes may be appropriately determined so as to generate the electrostatic force that keeps the rotor 40 stationary.

[Fourth modification of the embodiment]
The hands driven by the electrostatic motor 11 are not limited to the seconds hand 2 . The hands driven by the electrostatic motor 11 may be chronograph hands. In this case, the chronograph hands are stopped by the electrostatic motor 11 while the chronograph function is not in use. In other words, the control mode when the chronograph function is not used corresponds to the stop mode. Also, the control mode when the chronograph function is used is equivalent to the hand movement mode described above.

The electronic timepiece 1 may be configured such that the minute hand 3 and the hour hand 4 are driven by the electrostatic motor 11 in addition to the second hand 2 . In this case, in the stop mode, the minute hand 3 and hour hand 4 are stopped in addition to the second hand 2 .

Electronic timepiece 1 may be configured such that minute hand 3 and hour hand 4 are driven by a second electrostatic motor instead of electromagnetic motor 12 . In this case, the control circuit 20 moves the minute hand 3 and the hour hand 4 by the second electrostatic motor in the stop mode, and stops the electrostatic motor 11 .

The contents disclosed in each of the above embodiments and modifications can be executed in combination as appropriate. For example, in the electronic timepiece 1 of the first embodiment, in the stop mode, boosting by the booster circuit 15 may be stopped and a voltage lower than the voltage of the power supply 17 may be supplied to the electrostatic motor 11 . In the electronic timepiece 1 of the first embodiment, the boost factor in the stop mode may be lower than the boost factor in the hand movement mode. In the electronic timepiece 1 of the second embodiment, the number of boosting clocks of the boosting circuit 15 in the stop mode may be lower than the number of boosting clocks in the hand movement mode.

1 Electronic Clock 2 Second Hand 3 Minute Hand 4 Hour Hand 5 Train Wheel 11 Electrostatic Motor 12 Electromagnetic Motor 13 Electrostatic Motor Drive Circuit 14 Constant Voltage Source 15 Booster Circuit 16 Power Generation Mechanism 17 Power Supply 18 Operation Unit 20 Control Circuit 21 First Capacitor 22 Second Capacitor 23 Third capacitor 24 Fourth capacitor 25 First switch 26 Second switch 27 Third switch 28 Fourth switch 29 Fifth switch 30A Sixth switch 30B Seventh switch 31 Exterior case 32 Dial 33 Scale 34 Hour characters 35 Power saving Display 36 Charge Warning Display 40 Rotor 41 Rotating Shaft 42 Electret Film 42a Central Part 43 Through Hole 50 Stator 51 First Electrode 52 Second Electrode 53 Third Electrode 54 Electrode Group 60A First Stator 60B Second Stator 61 Second One electrode 62 Second electrode 63 Third electrode CW Direction of rotation F1, F11, F12, F13 Electrostatic attraction F2, F21, F22, F23, F24, F25, F26 Electrostatic repulsion

Claims (11)

a power supply;
an electrostatic motor having a rotor in which a plurality of electret films are arranged along the direction of rotation; and a plurality of fixed electrodes arranged in the direction of rotation at positions facing the rotor;
a pointer that rotates in conjunction with the rotation of the rotor;
a motor control circuit for controlling the electrostatic motor;
with
the motor control circuit selectively executes a hand operation mode in which the hands are rotated and a stop mode in which the hands are stopped;
In the stop mode, the motor control circuit stops the rotor by electrostatic force acting on the electret film from the fixed electrodes while maintaining the polarity of the fixed electrodes. tree,
further comprising an hour hand, a minute hand, and an electromagnetic motor for driving the hour hand and the minute hand;
the pointer that rotates in conjunction with the rotation of the rotor is a second hand;
In the stop mode, the hour hand and the minute hand are driven by the electromagnetic motor, and the rotation of the second hand is stopped.
An electronic clock characterized by: 2. The electronic device according to claim 1, wherein in the stop mode, the motor control circuit applies electrostatic attraction to the electret film by the counter electrode, which is the fixed electrode facing the central portion of the electret film. clock. 3. The electronic timepiece according to claim 2, wherein, in the stop mode, the motor control circuit causes an adjacent electrode, which is the fixed electrode adjacent to the counter electrode, to apply an electrostatic repulsive force to the electret film. a booster circuit for boosting the voltage of the power supply and supplying it to the electrostatic motor; and a voltage control circuit for controlling the booster circuit,
The electronic timepiece according to any one of claims 1 to 3, wherein the voltage control circuit reduces the power consumption of the booster circuit in the stop mode as compared to the power consumption of the booster circuit in the hand operation mode. 5. The electronic timepiece according to claim 4, wherein the voltage control circuit makes the number of clocks of the booster circuit in the stop mode smaller than the number of clocks of the booster circuit in the hand movement mode. 6. The electronic timepiece according to claim 4, wherein the voltage control circuit sets the boosting factor of the booster circuit in the stop mode lower than the boosting factor of the booster circuit in the hand operation mode. 5. The electronic timepiece according to claim 4, wherein the voltage control circuit stops boosting by the booster circuit in the stop mode, and supplies a voltage equal to or lower than the voltage of the power supply to the electrostatic motor. a power supply;
an electrostatic motor having a rotor in which a plurality of electret films are arranged along the direction of rotation; and a plurality of fixed electrodes arranged in the direction of rotation at positions facing the rotor;
a pointer that rotates in conjunction with the rotation of the rotor;
a motor control circuit for controlling the electrostatic motor;
with
the motor control circuit selectively executes a hand operation mode in which the hands are rotated and a stop mode in which the hands are stopped;
In the stop mode, the motor control circuit stops the rotor by an electrostatic force acting on the electret film from the fixed electrodes while maintaining the polarity of the fixed electrodes,
In the stop mode, the motor control circuit causes the counter electrode, which is the fixed electrode facing the central portion of the electret film, to apply electrostatic attraction to the electret film,
In the stop mode, the motor control circuit applies an electrostatic repulsive force to the electret film by the adjacent electrode, which is the fixed electrode adjacent to the counter electrode.
An electronic clock characterized by: a power supply;
an electrostatic motor having a rotor in which a plurality of electret films are arranged along the direction of rotation; and a plurality of fixed electrodes arranged in the direction of rotation at positions facing the rotor;
a pointer that rotates in conjunction with the rotation of the rotor;
a motor control circuit for controlling the electrostatic motor;
with
the motor control circuit selectively executes a hand operation mode in which the hands are rotated and a stop mode in which the hands are stopped;
In the stop mode, the motor control circuit stops the rotor by an electrostatic force acting on the electret film from the fixed electrodes while maintaining the polarity of the fixed electrodes,
a booster circuit for boosting the voltage of the power supply and supplying it to the electrostatic motor; and a voltage control circuit for controlling the booster circuit,
The voltage control circuit reduces the power consumption of the booster circuit in the stop mode to a level lower than the power consumption of the booster circuit in the hand operation mode,
The voltage control circuit makes the number of clocks of the booster circuit in the stop mode smaller than the number of clocks of the booster circuit in the hand movement mode.
An electronic clock characterized by: a power supply;
an electrostatic motor having a rotor in which a plurality of electret films are arranged along the direction of rotation; and a plurality of fixed electrodes arranged in the direction of rotation at positions facing the rotor;
a pointer that rotates in conjunction with the rotation of the rotor;
a motor control circuit for controlling the electrostatic motor;
with
the motor control circuit selectively executes a hand operation mode in which the hands are rotated and a stop mode in which the hands are stopped;
In the stop mode, the motor control circuit stops the rotor by an electrostatic force acting on the electret film from the fixed electrodes while maintaining the polarity of the fixed electrodes,
a booster circuit for boosting the voltage of the power supply and supplying it to the electrostatic motor; and a voltage control circuit for controlling the booster circuit,
The voltage control circuit reduces the power consumption of the booster circuit in the stop mode to a level lower than the power consumption of the booster circuit in the hand operation mode,
The voltage control circuit makes the boosting factor of the boosting circuit in the stop mode lower than the boosting factor of the booster circuit in the hand operation mode.
An electronic clock characterized by: a power supply;
an electrostatic motor having a rotor in which a plurality of electret films are arranged along the direction of rotation; and a plurality of fixed electrodes arranged in the direction of rotation at positions facing the rotor;
a pointer that rotates in conjunction with the rotation of the rotor;
a motor control circuit for controlling the electrostatic motor;
with
the motor control circuit selectively executes a hand operation mode in which the hands are rotated and a stop mode in which the hands are stopped;
In the stop mode, the motor control circuit stops the rotor by an electrostatic force acting on the electret film from the fixed electrodes while maintaining the polarity of the fixed electrodes,
a booster circuit for boosting the voltage of the power supply and supplying it to the electrostatic motor; and a voltage control circuit for controlling the booster circuit,
The voltage control circuit reduces the power consumption of the booster circuit in the stop mode to a level lower than the power consumption of the booster circuit in the hand operation mode,
The voltage control circuit stops boosting by the booster circuit in the stop mode, and supplies a voltage equal to or lower than the voltage of the power supply to the electrostatic motor.
An electronic clock characterized by:

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