WO2000077581A1

WO2000077581A1 - Electronic timepiece

Info

Publication number: WO2000077581A1
Application number: PCT/JP2000/003833
Authority: WO
Inventors: Fumio Nakajima
Original assignee: Citizen Watch Co., Ltd.
Priority date: 1999-06-14
Filing date: 2000-06-13
Publication date: 2000-12-21
Also published as: JP2003130972A

Abstract

After a driving circuit (13) excites a driving coil (14c) of a pulse motor (14) for hand drive to stepwise rotate a rotor (15r) by applying a plurality of driving pulses outputted from a waveform generating circuit, both ends of the driving coil (14c) are substantially short-circuited to generate a short-circuit current which is caused by the counter-electromotive force generated in the driving coil (14c) until the rotor (15r) stops, and a charging current corresponding to it is permitted to flow through a charging circuit (5) to charge the feedback capacitor (21) of an operational amplifier (20). The electric power stored in the charging circuit (5) is stored in a power source circuit (6), and the stored power is supplied to circuits that constitute the electronic timepiece such as the waveform generating circuit, the driving circuit (13), and the charging circuit (5).

Description

Document electronic clock

Technical field

The present invention relates to an analog electronic timepiece provided with a hand-operating pulse motor that operates using an oscillation signal of an oscillation circuit using a crystal oscillator as a reference signal. Background technology

Conventionally, an analog electronic timepiece has an oscillation circuit using a crystal oscillator that generates a reference signal, a frequency division circuit that divides the frequency of the reference signal of the oscillation circuit, and a drive pulse from the divided signal. A waveform generation circuit to generate, a driving circuit to input the driving pulse to drive the pulse motor stepwise, and hands (second hand, minute hand, and hour hand) to be rotated by the pulse motor through a train of gears ) Etc. The waveform generation circuit receives the frequency-divided signal from the frequency divider and generates and outputs multiple drive pulses with a frequency of 0.5 Hz, a wavelength of several milliseconds, and a phase difference of 180 degrees. . The drive circuit consists of two sets of complementary MOS transistors (hereafter abbreviated as "CMOST"). The pulse motor includes a drive coil having both ends connected to an output terminal of a drive circuit, a rotor made of a permanent magnet, and a soft magnetic material provided for magnetically coupling the drive coil to the rotor. Consists of a stator. The drive pulse output from the waveform generation circuit is alternately applied to each control terminal of the two sets of C MOSTs of the drive circuit, whereby the drive coil of the pulse motor is excited, and the rotor passes through the stator. A driving force is magnetically applied to With this driving force, the pulse motor rotates the rotor 180 degrees for each pulse. With the rotation of the rotor, the second hand, minute hand, and hour hand operate via a train of gears to display the time.

However, the conventional electronic timepiece configured as described above has the following problems. There was a problem.

The pulse motor for moving the hands of an electronic timepiece has a fixed magnetic force (magnetic potential) as a holding force between the stator and the rotor, which applies a drive pulse to the drive circuit. The rotor is prevented from rotating due to the rotating force (moment) generated on the hands, such as the second hand, even if an external impact is applied while it is not in operation.

Therefore, in order to rotate the rotor, by applying a drive pulse, the energy required for rotating the rotor itself is added to the energy required for rotating the rotor itself, and the energy required for rotating the train wheel connected to the rotor is added. Electricity must be supplied with energy that exceeds the amount of energy that overcomes the magnetic force (retention force) acting between the stator and the stator.

In this case, the amount of energy required for the rotation of the rotor itself and the rotation of the wheel train may be relatively small, such as about 0.05 microwatts in terms of electric energy. The energy required to overcome the magnetic force (coercive force) during this time is a relatively large value of about 0.4 microwatt in terms of electrical energy. Therefore, the electric power required to rotate the rotor also becomes a considerably large value of about 0.4 + 0.05 = 0.45 microwatts.

In addition, the total value of the power consumption in the oscillation circuit, the frequency divider circuit, and the waveform generation circuit is only about 0.05 microwatt, and in comparison with this, 0.4 is necessary for rotating the rotor. Electric power of about 5 microwatts is a large value. Most of the power required to rotate this rotor is only consumed to overcome the magnetic forces between the rotor and the stator, and is required for substantial rotation of the rotor or wheel train. It does not contribute and is wasted as friction loss after the rotor rotates.

Therefore, such an electronic watch has a total power consumption of about 0.5 microphone watts when viewed as a whole, and it is difficult to reduce the power consumption below this value. Most (approximately 0.4 microwatt) Force Rotor rotation There was a problem that it was wasted as friction loss later. Disclosure of the invention

An object of the present invention is to solve such a problem, to effectively use electric power in an analog electronic timepiece and to recover consumed electric power, and to substantially reduce substantial electric power consumption. is there.

The present invention relates to an oscillation circuit, a frequency dividing circuit for dividing the oscillation signal, a waveform generating circuit for generating a plurality of driving pulses based on the divided signal, and a driving circuit for inputting the plurality of driving pulses. In order to achieve the above object, in an electronic timepiece comprising: a driving coil that is excited by a driving current output from the driving circuit to rotate the rotor stepwise; A charging circuit that is charged by a short-circuit current based on the back electromotive force generated in the drive coil when the child stops rotating, stores the charged power in the charging circuit, and divides the stored power into the oscillation It has a circuit, a frequency divider, a waveform generator, a drive circuit, and a power supply circuit for supplying a charge circuit.

Therefore, according to the present invention, after the rotor of the pulse motor in the electronic timepiece rotates by a predetermined angle step, the electric power converted into kinetic energy until it is stopped by the magnetic holding force is supplied to the power supply via the charging circuit. The circuit can be efficiently recovered and reused, and the actual power consumption can be significantly reduced.

A switch that switches the charging circuit by a control pulse output from the waveform generation circuit when the short-circuit current occurs, and the switching of the switch causes a charging current to flow from an output terminal to an input terminal. An operational amplifier connected to the switch; and a feedback capacitor connected between an input terminal and an output terminal of the operational amplifier and charged when a charging current flows from the output terminal to the input terminal. can do.

Each of the drive circuits is driven by a plurality of drive pulses output by the waveform generation circuit. After the drive current is applied to the drive coil of the pulse motor by the plurality of drive pulses to rotate the rotor stepwise, each switch is connected to both ends of the drive coil. It is preferable to make a short circuit so as to have substantially the same potential, and to connect so as to generate a short circuit current based on the back electromotive force generated in the driving coil. The power supply circuit includes a backflow prevention diode and a secondary battery connected to the output side of the charging circuit, and the output voltage of the charging circuit decreases the forward voltage of the backflow prevention diode and the rechargeable battery. When the sum exceeds the terminal voltage, a charging current flows from the charging circuit to the secondary battery via the backflow prevention diode, and power is stored in the secondary battery.

Further, the power supply circuit may include a booster circuit that boosts a terminal voltage of the secondary battery and supplies the terminal voltage to the charging circuit as a power supply voltage.

Alternatively, when the short circuit current occurs, the charging circuit is charged by a charging current corresponding to the short circuit current, and charged by a charging voltage of the first charging circuit. It may be composed of a second charging circuit.

Further, a charging voltage of the charging circuit is detected, and when the detected voltage is equal to or lower than a predetermined value, a driving pulse having the same phase as the driving pulse output immediately before and having a higher driving power is loaded on the waveform generating circuit. By providing a load compensation loop that continuously outputs compensation pulses, it is possible to prevent hand movement failure due to insufficient driving force of the pulse motor. BRIEF DESCRIPTION OF THE FIGURES

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

FIG. 2 is a circuit diagram showing a specific example of a circuit diagram showing a drive circuit of the electronic timepiece, a pulse motor and a charging circuit.

FIG. 3 is a circuit diagram showing a specific example of a power supply circuit of the electronic timepiece. FIG. 4 is a timing chart showing waveforms of a drive pulse, a control pulse, and the like generated from the waveform generation circuit of the electronic timepiece.

5A to 5C are explanatory diagrams in a first phase for explaining an operation of charging the charging circuit based on the back electromotive force of the pulse motor by the circuit shown in FIG. FIGS. 6A to 6C are explanatory diagrams in the second phase for explaining the operation of charging the charging circuit based on the back electromotive force of the pulse motor.

FIG. 7 is a block diagram showing an overall configuration of a second embodiment of an electronic timepiece according to the present invention.

FIG. 8 is a circuit diagram of a drive circuit, a pulse motor and a charging circuit of a third embodiment of the electronic timepiece according to the present invention.

FIG. 9 is a block diagram showing the overall configuration of an electronic timepiece according to a fourth embodiment of the present invention. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out an electronic timepiece according to the present invention will be described in detail with reference to the accompanying drawings.

[First Embodiment: FIGS. 1 to 6C]

FIG. 1 is a block diagram showing an overall configuration of an electronic timepiece according to a first embodiment of the present invention, FIG. 2 is a circuit diagram showing an example of a drive circuit and a pulse motor and a charging circuit, and FIG. It is a circuit diagram showing an example. FIG. 4 is a timing chart showing waveforms of a drive pulse and a control pulse generated from the waveform generation circuit of the electronic timepiece. FIGS. 5A to 5C and FIGS. 6A to 6A FIG. 6C is an explanatory diagram in a first phase and a second phase for explaining an operation of charging the charging circuit based on the back electromotive force of the pulse motor.

As shown in FIG. 1, the electronic timepiece according to the first embodiment includes an oscillation circuit 1, a frequency dividing circuit 2, a waveform generating circuit 3, a driving circuit and a pulse motor 4, a charging circuit 5, and a power supply circuit. Consists of six.

The oscillation circuit 1 oscillates a crystal oscillator (not shown) at a reference frequency, outputs a reference signal S 0 having the reference frequency, and inputs the reference signal S 0 to the frequency dividing circuit 2.

The frequency dividing circuit 2 is connected to the output terminal of the oscillation circuit 1, inputs the reference signal S0, divides the frequency to a frequency lower than the reference frequency, and outputs the frequency-divided signal S1.

The waveform generating circuit 3 is connected to the output terminal of the frequency dividing circuit 2 and receives the frequency-divided signal S1 and outputs four driving pulses φ1 to φ4, which will be described later, and first control pulses φ5 and ψ6. And the second control pulses ψ7 and φ8 are generated and output.

The drive circuit and the pulse motor 4 input four drive pulses φ 1 to φ 4 from the waveform generation circuit 3 and drive the pulse motor to move hands such as the second hand, minute hand, and hour hand. The charging circuit 5 is connected to the drive circuit and the output side of the pulse motor 4, and receives the first control pulses ψ5 and φ6 from the waveform generation circuit 3.

The power supply circuit 6 is connected to the output side of the charging circuit 5, receives the second control pulses φ 7 and φ 8 from the waveform generation circuit 3, and receives an oscillation circuit 1, a frequency division circuit 2, Power is supplied to the waveform generation circuit 3, the drive circuit and the pulse motor 4, and also to the charging circuit 5 via the power supply line 8.

Next, a specific configuration example of the drive circuit and the pulse motor 4 and the charging circuit 5 in FIG. 1 will be described with reference to FIG.

In the following description, “PM〇ST” is an abbreviation for a P-channel type M〇S transistor, and “NMOST” is an abbreviation for an N-channel type MOS transistor.

The driving circuit 13 in the driving circuit and the pulse motor 4 is composed of PMOSTs 9 and 10 and NMOSTs 11 and 12 which constitute a first switch group. The drains of the PMOST 9 and the NMO ST 11 are connected to each other to form a connection terminal A, and the drains of the PMO ST 10 and the NMO ST 12 are connected to each other as a connection terminal B. The sources of PMO ST 9 and PMO ST 10 are both connected to the power supply line 、, and the sources of NMO ST 11 and NMO ST 12 are both grounded. Then, four drive pulses φ 1 to φ 4 generated by the waveform generation circuit 3 are input to the drive circuit 13. Drive pulse ψ 1 is applied to the control terminal (gate) of NM〇 ST 12 to drive NMO ST 12, and drive pulse φ 2 is applied to the input control terminal (gate) of NM〇 ST 11 To drive NMO ST11. Drive pulse # 3 is applied to the control terminal of PMO ST 10 to drive PMO ST 10 and drive pulse # 4 is applied to the input control terminal of PMO ST 9 to drive PMO ST 9.

The pulse motor 14 includes a drive coil 14c, a stator 14s, and a rotor 14r. The drive coil 14 c has both ends connected to the connection terminal A and the connection terminal B of the drive circuit 13, respectively, and is excited by a signal input through these connection terminals A and B to form a rotor 14 r. To rotate.

The charging circuit 5 is composed of switches 18 and 19 made of MOS transistors constituting a second switch group, an operational amplifier 20 and a feedback capacitor 21.

In the switch 18, the connection line 16 connected to the connection terminal B is connected to the input terminal, and the output terminal is connected to the minus input terminal of the operational amplifier 20. Further, a first control pulse Φ 5 is input to the control terminal which is the gate. In the switch 19, the connection line 17 similarly connected to the connection terminal A is connected to the input terminal, and the output terminal is connected to the minus input terminal of the operational amplifier 20. Further, the first control pulse φ 6 is input to the control terminal which is the gate.

In the operational amplifier 20, the output terminals of the switches 18 and 19 are connected to the minus input terminal, and the plus input terminal is grounded. Then, the output terminal is connected to the connection line 22. The negative input terminal and the output terminal of the operational amplifier 20 are connected via a feedback capacitor 21. Next, the configuration of a specific example of the power supply circuit 6 in FIG. 1 will be described in detail with reference to FIG.

As shown in FIG. 3, the power supply circuit 6 includes a diode 23 for preventing backflow, a secondary battery 24, and a booster circuit 25.

The connection line 22 is connected to the anode of the diode 23, and the positive terminal of the secondary battery 24 and the power supply line 7 are connected to the power source. The negative terminal of the secondary battery 24 is grounded. Therefore, the positive terminal of the secondary battery 24 is connected to each of the oscillation circuit 1, the frequency dividing circuit 2, the waveform generating circuit 3, the driving circuit and the pulse motor 4 via the power supply line 7, and the positive terminal is connected to these. Voltage is being applied.

The booster circuit 25 includes MOS transistors 26 to 29, a capacitor 30 and a capacitor 31.

The MOS transistor 26 has one terminal connected to the positive terminal of the secondary battery 24 and the other terminal connected to one terminal of the MOS transistor 27 via the capacitor 30. Further, the second control pulse # 7 is input to the control terminal which is a gate. The other terminal of the MOS transistor 27 is grounded. Then, a second control pulse φ8 is input to the control terminal that is a gate.

The MOS transistor 28 has one terminal connected to the positive terminal of the capacitor 31 and the other terminal connected to the positive terminal of the capacitor 30. The MOS transistor 29 has one terminal connected to one terminal of the MOS transistor 26 and the negative terminal of the capacitor 31, and the other terminal connected to the negative terminal of the capacitor 30 and one terminal of the MOS transistor 27. Terminal. Further, the second control pulse # 8 is input to the control terminals that are the gates of the MOS transistors 28 and 29. The positive terminal of the capacitor 31 is connected to the positive voltage terminal of the operational amplifier 20 constituting the charging circuit 5 shown in FIG. 2 via the power supply line 8, and the negative terminal is connected to the MOS transistors 29, 26. Are connected to one terminal. Next, the operation of the electronic timepiece configured as described above will be described with reference to FIGS. 4, 5A to 5C, and 6A to 6C. In the following description, the waveforms of the respective pulses output from the waveform generation circuit 3 will be described in the order shown in FIG.

First, the operation of the drive circuit and the pulse motor 4 shown in FIG. 2 will be described. The drive pulse ψ1 shown in FIG. 4 is initially at a high level, and the input NMOST12 becomes conductive (hereinafter referred to as “on”). In this state, time t! From! Until ^, the drive pulse φ 4 is at the mouth level, so that PMOST 9 for inputting it is turned on.

At this time, as shown in FIG. 5A, the drive current id flows through the drive coil 14c of the noise motor 14 from the connection terminal A to the connection terminal B. The stator current 14 s is excited by the flow of this drive current id, and the rotor 14 r is equivalent to the kinetic energy of the magnetic force (magnetic potential) which is the holding force between the stator 14 s and the stator 14 s. It rotates beyond 180 degrees due to the driving force. However, after being returned by the holding force and vibrating, it stops at a position rotated 180 degrees.

At this time, the voltage VA shown in FIG. 4 at the connection terminal Α should be at the same potential as the power supply voltage is applied from the power supply line 7, but actually flows through the drive coil 14c. The potential is obtained by subtracting the induced voltage E of the opposite polarity generated so as to impede the drive current i.

Next, after time t = t _2, the drive pulse phi 4 is to return to a high level, PMOST 9 returns to the non-conducting state (hereinafter referred to as "off"). Then, the drive current i from the connection terminal A to the connection terminal B does not flow through the drive coil 14 c.

In the above case, the rotor 14 r makes a rotary motion exceeding 180 degrees of the predetermined angle, but the rotor 14 r performs the rotary motion in the stator 14 s, thereby Back electromotive force is generated in coil 14c, and induced voltage F shown in Fig. 4 is generated at connection terminal A. I do. This induced voltage F has the opposite polarity to the induced voltage E. Also, the drive pulse φ2 remains at the mouth-level, the NMOST 11 remains off, and the drive pulse ψ3 remains at the low level, so that the PMOST 10 remains off.

The first control pulse phi 6 shown in FIG. 4 is, to become a high level in a period from time t = t ₃ of t _4, which conducts switch 1 9 charging circuit 5. The connection state of the charging circuit 5 is as shown in FIG. 5B.

At this time, the switch 19 is turned on, and the connection from the connection terminal A to the negative input terminal of the operational amplifier 20 is conducted, but the plus input terminal of the operational amplifier 20 is grounded and the The negative input terminal of the amplifier 20 has the same ground potential as the positive input terminal due to a virtual short (high impedance and no current flows inside), so the connection terminal A is also at the ground potential. Further, since the driving pulse ψ1 remains at a high level, NMOST12 remains on, and the connection terminal B is at the ground potential. Therefore, both ends of the drive coil 14c of the pulse motor 14 connected between the connection terminals A and B are substantially short-circuited.

When both ends of the drive coil 14 c are substantially short-circuited, the drive coil 14 c is induced by the rotational motion of the rotor 14 r with respect to the magnetic force between the rotor 14 r and the stator 14 s. Electric power is generated, and a short-circuit current i _{S l} flows as shown in FIG. 5B. The short-circuit current i _{S l} causes a charging current i _{C l} to flow from the output terminal of the operational amplifier 20 to the minus input terminal, The feedback capacitor 21 is charged.

Subsequently, at time t = t4 shown in FIG. ₄ , the first control pulse ψ6 returns to the low level, so that the switch 19 is turned off, and the charging circuit 5 is turned off by the driving circuit 13 (the second (Fig.)

Further, at time t = t _5, since the drive pulse phi 2 becomes high level, NMO ST 1 1 which receives the is turned on, the driving circuit 1 3 becomes the connected state shown in 5 C Figure. At this time, both ends of the drive coil 13 are grounded. Further subsequently, at time t = t _6, the drive pulse [psi 3 becomes frontage first level until a time t = t _7, PMOST 1 0 is turned on to enter it. Further, when it becomes a time t = t _s, the drive pulse phi 1 the time t = t,. NM OS Τ 1 2 will be turned off.

Therefore, the drive circuit 13 is as shown in Fig. 6 and the power supply voltage is input from the power supply line 7 to the connection terminal B, and the drive coil 14c is driven from the connection terminal B to the connection terminal A. The current id ₂ flows. When the drive current id ₂ flows, the stator 14 s is excited, and the rotor 14 r is driven by a driving force corresponding to a kinetic energy equal to or greater than a magnetic potential which is a holding force between the stator 14 s and the stator 14 s. In response, it rotates beyond 180 degrees. At this time, the voltage VB shown in FIG. 4 at the connection terminal B should be the same as the power supply voltage from the power supply line 7 since the power supply voltage is applied to the connection terminal B. It becomes a potential obtained by subtracting the induced voltage G of opposite polarity generated so as to prevent the driving current id _2.

Then, past the Tokii ij t = t _7, the drive pulse phi 3 is to return to a high level, PMOST 1 0 returns to OFF. Then, the drive current id ₂ stops flowing.

In the above case, the rotor 14 r overcame the magnetic potential, which is the holding force between the stator 14 s, and rotated beyond 180 degrees, so that the driving coil 14 r An electromotive force is generated at c, and an induced voltage H shown in FIG. This induced voltage H has the opposite polarity to the induced voltage G.

Thereafter, between times t = t ₈ forces et t _9, because the first control pulse phi 5 ing the high level, Suitsuchi 1 8 of the charging circuit 5 is turned on, the driving circuit 1 3 the first 6 B Figure It becomes as shown in.

At this time, the switch 18 conducts and the connection terminal B to the minus input terminal of the operational amplifier 20 are turned on, but the plus input terminal of the operational amplifier 20 is grounded and the minus terminal of the operational amplifier 20 is connected. Input terminal is positive input terminal due to virtual short. It has the same potential as the child. Also, since the drive pulse φ2 remains at the high level, the NMOST 11 remains on, and the connection terminal A is at the ground potential. Therefore, both ends of the drive coil 14c connected between the connection terminals A and B are substantially short-circuited.

When both ends of the drive coil 14 c are substantially short-circuited, the magnetic force between the rotor 14 r and the stator 14 s induces the drive coil 14 c by the rotational motion of the rotor 14 r. and power is generated, the 6 B is short-circuit current iS ₂ flows as shown in the illustration connexion by this short-circuit current iS _2, a charging current ics ₂ flows from the output terminal of the operational amplifier 2 0 to a minus input terminal, a feedback The capacitor 21 is charged again.

Subsequently, at a Tokii 'J t = t _9, since the first control pulse [psi 5 returns to the mouth first level, Suitsuchi 1 8 is turned off, the charging circuit 5 is disconnected from the driving circuit 1 3.

Also, time t = t,. At this time, the drive pulse φ 1 becomes high level, so that NMOST 12 for inputting it is turned on, and the drive circuit 13 is brought into the connection state shown in FIG. 6C. At this time, both ends of the drive coil 14c are grounded.

Thereafter, the above operation is repeated. Each time drive pulses ^) 1 to φ 4 are applied to the drive circuit 13, the power supplied from the power supply circuit 6 to the drive circuit 13 through the power supply line 7 causes the rotor of the pulse motor 14 to rotate. 14 r rotates with the kinetic energy. The kinetic energy corresponding to the magnetic force (magnetic potential) is converted into the electromotive force generated in the drive coil 14c by the rotation of the rotor 14r, and the electromotive force is generated by the electromotive force. The short-circuit current is charged in the feedback capacitor 21 of the charging circuit 5.

Therefore, charging is performed each time the drive pulses # 1 to # 4 are applied to the drive circuit, and the power supplied from the power supply circuit 6 can be prevented from being wasted as friction loss.

In this way, the feedback capacitor 21 is repeatedly charged by the short-circuit current. In order to continue, the output voltage of the charging circuit 5 eventually becomes higher than the voltage of the secondary battery 24 shown in FIG.

At this time, the booster circuit 25 in FIG. 3 charges the capacitor 30 and the capacitor 31 by the second control pulse ψ7 and φ8. That is, when the second control pulse φ7 is input and the MOS transistor 26 is turned on, the output voltage of the charging circuit 5 is charged in the capacitor 30. When the second control pulse ψ8 is also turned on, the MOST 2 7, 28, and 29 are turned on, and the capacitor 31 is charged with the output voltage of the charging circuit 5. As described above, since the booster circuit 25 boosts the output voltage of the power supply line 7 about twice as much as the output voltage of the power supply line 8, even if the charging voltage of the feedback capacitor 21 of the charging circuit 2 becomes higher, Then, a voltage higher than the voltage of the power supply line 7 is supplied from the booster circuit 25 to the operational amplifier 20 so that the operational amplifier 20 operates.

In addition, the charge due to the short-circuit current continues to be repeatedly charged in the feedback capacitor 21 in FIG. 2, and the sum of the output voltage of the operational amplifier 20 and the forward drop voltage of the diode 23 for backflow prevention in FIG. When the output voltage of the secondary battery 24 of the power supply circuit 6 exceeds the output voltage, a current flows from the feedback capacitor 21 to the secondary battery 24 through the diode 23 for preventing backflow, and as extra power, The power stored in the feedback capacitor 21 is recovered by being stored in the secondary battery 24. Therefore, the power consumption of the entire electronic timepiece can be substantially reduced significantly, and the battery life of the electronic timepiece using the secondary battery can be extended.

[Second embodiment: Fig. 7]

Next, a second embodiment of the electronic timepiece according to the present invention will be described.

Since the electronic timepiece is substantially common to the electronic timepiece of the first embodiment, only differences will be described, and description of common points will be omitted or simplified. The electronic timepiece of this embodiment is provided with a load compensation loop including a detection circuit 40, load compensation lines 41 and 42, and a waveform generation circuit 3 'between the charging circuit 5 and the waveform livelihood circuit 3. However, unlike the electronic timepiece of the first embodiment, other configurations are the same. The detection circuit 40 detects the charging voltage of the charging circuit 5, controls the waveform generation circuit 3 'according to the detection result, and has the same phase as the driving pulse <i> 1 to φ4 output immediately before. The drive pulses φ 1 to φ 4 with load compensation are output continuously.

More specifically, the detection circuit 40 outputs a load compensation signal to the waveform generation circuit 3 ′ when the voltage (charging voltage) charged in the feedback capacitor 21 of the charging circuit 5 is equal to or lower than a certain value. To perform load compensation. The load compensation is performed as follows.

Like the electronic timepiece of the first embodiment, during the period from the time t = ti in Figure 4 until t _2, the driving current that passes the drive pulse phi 4 is applied to the drive circuit and the pulse motor 4, The charging circuit 5 is charged by applying the control pulse ψ6 from time t = t3 to t4.

The charging voltage at this time is detected by the detection circuit 40 via the load compensation line 41 for each drive, and when the detection voltage is equal to or lower than a certain voltage, the detection circuit 40 outputs the waveform generation circuit 3 'Outputs a load compensation signal to the waveform generation circuit 3', which has the same phase as the driving pulse output immediately before and has higher power than the normal (stationary) driving pulse (whether the pulse width is wider or the wave height is higher). High or shoving density is high.) The driving circuit and the pulse motor 4 drive the pulse motor 14 with the driving pulse with a stronger driving force than the previous time. Thus, even if the driving force of the pulse motor 14 is insufficient and the stepping of the hands is not reliably performed, the hands can be driven again with a larger driving force to surely advance the hands.

Also in this case, the power consumed after driving the pulse motor 14 can be recovered, and the unnecessary power consumption can be suppressed. [Third embodiment: Fig. 8]

Next, a third embodiment of the electronic timepiece according to the present invention will be described.

As shown in FIG. 8, the electronic timepiece differs from the charging circuit 5 in the first embodiment in that the charging circuit 45 is different from the charging circuit 5 in the first embodiment. Except that ψ9 is input in addition to 55 and 66, this embodiment is the same as the first embodiment described above. Therefore, only the differences will be described, and description of the common points will be omitted.

The charging circuit 45 shown in FIG. 8 has a switch 46 composed of a MOS transistor, an operational amplifier 47 and a feedback capacitor 48 as compared with the charging circuit 5 in the first embodiment. They differ in that they have two sets of amplifiers and feedback capacitors.

The switch 46 has an input terminal connected to the output terminal of the operational amplifier 20, an output terminal connected to the negative input terminal of the operational amplifier 47, and a first control pulse ψ 9 applied to a control terminal serving as a gate. Input from the waveform generation circuit 3. In the operational amplifier 47, the output terminal of the switch 46 is connected to the negative input terminal, and the positive input terminal is grounded. The output terminal is connected to a connection line 22 to the power supply circuit 6. The feedback capacitor 48 is connected between the negative input terminal of the operational amplifier 47 and the output terminal.

The electronic timepiece according to the third embodiment is configured as described above, and the operation is as follows. Similarly to the electronic timepiece according to the first embodiment, the electronic timepiece according to this embodiment is also configured such that the feedback capacitor 21 is first activated by the short-circuit current caused by the induced power generated in the drive coil 14 c of the pulse motor 14. Charged.

In this case, the feedback capacitor 21 is charged each time a short-circuit current is generated and the first control pulse φ 5, 06 is repeatedly turned on and off. When the charge stored in the feedback capacitor 21 reaches a predetermined charge amount and charging is completed, the first control pulse <ί> 9 Therefore, switch 46 is turned on. Then, the charge stored in the feedback capacitor 21 passes through the switch 46 and is charged in the feedback capacitor 48.

By repeatedly charging the feedback capacitor 48, the sum of the output voltage of the operational amplifier 47 and the forward voltage drop of the backflow prevention diode 23 shown in FIG. When the output voltage exceeds 24, the charge stored in the feedback capacitor 48 is stored in the secondary battery 24, and the power stored in the feedback capacitor 21 as extra power is supplied to the power supply. Collected in circuit 6.

As described above, according to the electronic timepiece of the third embodiment, since the electric charge can be stored not only by the feedback capacitor 20 but also by the feedback capacitor 48, the electric charge stored in the feedback capacitor 20 may exceed the allowable amount. Even if there is, the excess amount can be recovered by the feedback capacitor 48, so that the power can be recovered more reliably and wasteful power consumption can be suppressed.

[Fourth embodiment: Fig. 9]

Next, a fourth embodiment of the electronic timepiece according to the present invention will be described.

As shown in FIG. 9, this electronic timepiece is provided with a charging circuit 45 instead of the charging circuit 5 in the second embodiment shown in FIG. The only difference from the electronic timepiece of the second embodiment is that φ9 is input in addition to ψ5 and φ6 from the circuit 3 "as the first control pulse. This is the same as the third embodiment described.

The functions of the detection circuit 40 forming the load compensation loop and the waveform generation circuit 3〃 are the same as those of the second embodiment, but the waveform generation circuit 3〃 has a function other than φ5 and 6 as the first control pulse. To output Φ9. This is also the same as in the third embodiment.

The electronic timepiece according to the fourth embodiment has the configuration of both the electronic timepiece according to the second embodiment and the electronic timepiece according to the third embodiment. Therefore, power can be recovered more reliably, and wasteful power consumption can be significantly reduced. it can. In addition, it is possible to prevent the pointer from running poorly due to insufficient driving force of the pulse motor.

In the above description of the embodiment, an example has been described in which the booster circuit provided in the power supply circuit generates a voltage approximately twice that of the secondary battery by using the control pulse of the waveform generation circuit. The present invention is not limited to this embodiment, and a booster circuit that does not require an external control pulse may be used. Also, since this booster circuit is not essential, it need not be provided. Industrial applicability

As is apparent from the above description, the electronic timepiece according to the present invention is configured such that the energy generated by the back electromotive force generated in the drive coil due to the extra rotation of the rotor of the pulse motor after the application of the drive pulse is equivalent to the both ends of the drive coil The charging circuit can be charged by the short-circuit current obtained by short-circuiting the battery, and it can be further recovered in the secondary battery of the power supply circuit. Therefore, of the electric power supplied from the power supply circuit to operate the pulse motor, the electric power converted into the kinetic energy of the rotor after the rotor has rotated by the predetermined angle is not wasted, and the power supply circuit is not used again. It can be efficiently collected in the secondary battery. As a result, not only can the actual power consumption of the electronic watch be significantly reduced, but also the battery life of the electronic watch using the secondary battery can be prolonged. A stop situation can be prevented.

It is also possible to use a smaller secondary battery and make the timepiece mechanism smaller to give a variety of designs such as exterior shapes.

Claims

The scope of the claims

1. Oscillator circuit, frequency dividing circuit for dividing the oscillation signal, waveform generating circuit for generating a plurality of driving pulses by the divided signal, driving circuit for inputting the plurality of driving pulses, and driving An electronic timepiece including a pulse motor for moving a hand that excites a driving coil by a driving current output from a circuit and rotates a rotor in steps.

A charging circuit that is charged by a short-circuit current based on a back electromotive force generated in the drive coil when the rotation of the rotor of the pulse motor stops.

And a power supply circuit for storing the charged power in the charging circuit, and supplying the stored power to the oscillation circuit, the frequency dividing circuit, the waveform generating circuit, the driving circuit, and the charging circuit. Electronic clock.

2. In the electronic timepiece according to claim 1,

A switch that is switched by a control pulse output by the waveform generation circuit when the short-circuit current occurs,

An operational amplifier connected to the switch so that a charge current flows from the output terminal to the input terminal when the switch is switched;

A feedback capacitor connected between an input terminal and an output terminal of the operational amplifier and charged when a charging current flows from the output terminal to the input terminal;

An electronic timepiece comprising:

3. In the electronic timepiece according to claim 1,

The drive circuit includes a plurality of switches each of which is switched by a plurality of drive pulses output by the waveform generation circuit,

After each of the switches causes a drive current to flow through the drive coil of the pulse motor by the plurality of drive pulses to rotate the rotor stepwise, both ends of the drive coil are rotated. An electronic timepiece which is substantially short-circuited so as to have the same potential and is connected so as to generate a short-circuit current based on a back electromotive force generated in the drive coil.

4. In the electronic timepiece according to claim 2,

After each of the switches causes a drive current to flow through the drive coil of the pulse motor by the plurality of drive pulses to rotate the rotor stepwise, both ends of the drive coil are substantially short-circuited so as to have the same potential. An electronic timepiece connected to generate a short-circuit current based on a back electromotive force generated in the drive coil.

5. In the electronic timepiece according to claim 1,

The power supply circuit includes a backflow prevention diode connected to an output side of the charging circuit and a secondary battery,

When the output voltage of the charging circuit exceeds the sum of the forward voltage drop of the backflow prevention diode and the terminal voltage of the secondary battery, the charging circuit sends the second signal through the backflow prevention diode. An electronic timepiece, wherein a charging current flows to a secondary battery and power is stored in the secondary battery.

6. In the electronic timepiece according to claim 2,

When the output voltage of the charging circuit exceeds the sum of the forward voltage drop of the backflow prevention diode and the terminal voltage of the secondary battery, the secondary battery is supplied from the charging circuit via the backflow prevention diode. An electronic timepiece, wherein a charging current flows through the secondary battery and power is stored in the secondary battery.

7. The electronic timepiece according to claim 5,

An electronic timepiece, wherein the power supply circuit includes a booster circuit that boosts a terminal voltage of the secondary battery and supplies the terminal voltage to the charging circuit as a power supply voltage.

8. The electronic timepiece according to claim 6,

9. In the electronic timepiece according to claim 1,

A first charging circuit that is charged by a charging current corresponding to the short-circuit current when the short-circuit current occurs; and a second charging circuit that is charged by a charging voltage of the first charging circuit. An electronic timepiece comprising a charging circuit.

10. The electronic timepiece according to claim 1,

When the charging voltage of the charging circuit is detected and the detected voltage is equal to or lower than a predetermined value, the waveform generating circuit outputs a driving pulse having the same phase as the driving pulse output immediately before and having a higher driving power to the load compensation pulse. An electronic timepiece provided with a load compensation loop for continuously outputting as follows.

1 1. In the electronic timepiece according to claim 2,

1 2. In the electronic timepiece according to claim 9,

The charging voltage of the first charging circuit is detected, and when the detected voltage is equal to or lower than a predetermined value, the waveform generating circuit outputs the same driving phase as that of the driving pulse output immediately before, thereby reducing the driving power. An electronic timepiece provided with a load compensation loop for continuously outputting a large drive pulse as a load compensation pulse.