Mechanical watch

Abstract

To provide a mechanical watch that can control the rotation of a rotor in conjunction with a balance wheel to improve electromotive voltage in performing power generation and speed control.SOLUTION: A mechanical watch comprises: a spring; a first gear train that transmits power from the spring; hands that are driven by the first gear train and display time; a balance wheel that is driven via the first gear train; a first rotor that rotates in conjunction with the balance wheel; a first coil that applies brake force to the balance wheel via the first rotor and generates electric energy; a first charging circuit that intermittently short-circuits both ends of the first coil on the basis of a control signal to control the speed of the balance wheel, and executes chopping control of boosting the voltage of the electric energy generated by the first coil; control means that outputs the control signal to the first charging circuit; and a power storage device that stores the electric energy output from the first charging circuit.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a mechanical timepiece having a balance. [Background technology]

[0002] Patent Document 1 discloses a mechanical timepiece that includes a rotor attached to the balance shaft of a balance wheel that is driven by power from a power source, and a coil; electricity is generated by the rotation of the rotor that accompanies the forward and reverse rotation of the balance wheel; and speed-regulating pulses are output to the coil based on a rotation detection signal from the rotor to control the movement of the rotor. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] International Publication No. 2022 / 176453 Summary of the Invention [Problem to be solved by the invention]

[0004] In the mechanical watch of Patent Document 1, the power-generating rotor rotates in conjunction with the forward and reverse rotation of the balance wheel, so the rotation speed cannot be increased, which could result in an insufficient power generation capacity of the generator and a lack of power required to operate the control circuit. [Means for solving the problem]

[0005] The mechanical timepiece disclosed herein is characterized by comprising a mainspring, a first train wheel that transmits power from the mainspring, hands that are driven by the first train wheel and display the time, a balance wheel that is driven via the first train wheel, a first rotor that rotates in conjunction with the balance wheel, a first coil that applies braking force to the balance wheel via the first rotor and generates electrical energy, a first charging circuit that executes chopping control that regulates the speed of the balance wheel and boosts the electrical energy generated by the first coil by intermittently short-circuiting both ends of the first coil based on a control signal, control means that outputs the control signal to the first charging circuit, and a power storage device that stores the electrical energy output from the first charging circuit. [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a front view showing a mechanical timepiece according to a first embodiment. [Figure 2] FIG. 1 is a schematic perspective view showing the configuration of a main part of a first embodiment. [Figure 3] 3A to 3C are diagrams illustrating the operations of the pallet fork, escape wheel, balance, and first rotor of the first embodiment. [Figure 4] 3A to 3C are diagrams illustrating the operations of the pallet fork, escape wheel, balance, and first rotor of the first embodiment. [Figure 5] FIG. 1 is a block diagram showing a circuit configuration of a first embodiment. [Figure 6] FIG. 2 is a circuit diagram showing a configuration of a first charging circuit of the first embodiment. [Figure 7] FIG. 4 is a waveform diagram showing a control signal output from a control circuit to a first charging circuit in the first embodiment. [Figure 8] 4 is a timing chart showing a coil voltage, a rotation detection signal, a reference clock signal, and a control signal in the first embodiment. [Figure 9] 4 is a graph showing the relationship between brake duty and power generation voltage in the first embodiment. [Figure 10] FIG. 10 is a block diagram showing the configuration of a mechanical timepiece according to a second embodiment. [Figure 11]FIG. 10 is a schematic perspective view showing the configuration of the main part of a second embodiment. [Figure 12] FIG. 10 is a block diagram showing a circuit configuration of a second embodiment. [Figure 13] 10 is a flowchart showing a control according to a second embodiment. [Figure 14] FIG. 10 is a block diagram showing the configuration of a mechanical timepiece according to a third embodiment. [Figure 15] FIG. 10 is a schematic view showing the configuration of a main part of a third embodiment. [Figure 16] FIG. 10 is a block diagram showing a circuit configuration of a third embodiment. [Figure 17] FIG. 10 is a circuit diagram showing a configuration of a first charging circuit according to a modified example. [Figure 18] 10 is a timing chart showing a coil voltage, a rotation detection signal, a reference clock signal, and a control signal in a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0007] [First embodiment] A mechanical timepiece 1 of the first embodiment will be described below with reference to the drawings. As shown in FIG. 1, the mechanical timepiece 1 includes a case 2, a dial 3, an hour hand 4, a minute hand 5, a second hand 6, a crown 7, and a date wheel 8. The mechanical timepiece 1 is equipped with a movement 10 shown in Fig. 2. The movement 10 is equipped with a power spring 12, a first train wheel 20, an escape wheel 21, an anchor 22, a balance wheel 30, and a generator governor 60, and an hour hand 4, a minute hand 5, and a second hand 6 are attached to the first train wheel 20.

[0008] Power spring 12 is housed in barrel complete 11, which is made up of barrel wheel 13, barrel arbor 14, and barrel cover. The outer end of mainspring 12 is fixed to barrel wheel 13, and the inner end is fixed to barrel arbor 14. Barrel arbor 14 is inserted into a support member provided on the main plate and fixed with a square socket screw, and rotates integrally with ratchet wheel 15. Racket wheel 15 is rotated by crown 7 via crown wheel 16 and the like, and mainspring 12 is wound up.

[0009] The rotation of the barrel gear 13 is accelerated via the gears of the center wheel & pinion 17, the third wheel & pinion 18, and the fourth wheel & pinion 19. The center wheel & pinion 17, the third wheel & pinion 18, and the fourth wheel & pinion 19 are journaled by the main plate and the train wheel bridge, and together they form a first train wheel 20 that transmits mechanical energy from the mainspring 12. Note that while Figure 2 only shows the second hand 6 fixed to the second pinion that meshes with the third wheel & pinion 18, in reality, there are also minute hand 5 and hour hand 4 that are driven via a cannon pinion and hour wheel (not shown). The movement 10 comprises an escapement with an escape wheel 21 and an anchor 22, and a regulator with a balance wheel 30. The escapement supplies mechanical energy from the mainspring 12 via a second wheel 19 to the regulator little by little to maintain the vibration of the regulator, and controls the rotational speed of the first train wheel 20 according to the vibration period of the regulator.

[0010] The balance 30 comprises a balance wheel 31, a balance arbour 33, and a hairspring 34. The balance 30 has a thin hairspring 34 fitted inside the balance wheel 31, one end of which is fixed to the balance arbour 33, which is the axis of the balance wheel 31, and the other end of which is fixed to the watch body via a hairspring 39. The balance wheel 31 of the balance 30 oscillates by repeating regular reciprocating rotational motion due to the expansion and contraction of the isochronous hairspring 34. In this embodiment, the balance 30 oscillates through an oscillation angle of 280°.

[0011] The generator / speed governor 60 includes a first rotor 61 for generating electricity and speed regulation attached to the balance shaft 33, a stator 62 defining an opening in which the first rotor 61 is placed, a magnetic core 63 having both ends fixed to the stator 62, a first coil 64 wound around the magnetic core 63, and terminals 65, 66 to which both ends of the first coil 64 are electrically connected. The generator governor 60 is an electromagnetic generator in which the first rotor 61 rotates together with the balance axle 33 using mechanical energy transmitted from the mainspring 12 via the first train wheel 20 to the balance wheel 30, thereby changing the direction of the magnetic lines of force flowing through the stator 62 and the magnetic core 63 and generating induced electric power in the first coil 64.

[0012] 3 and 4 are diagrams for explaining the movements of the escape wheel 21, the pallet fork 22, the balance 30, and the first rotor 61. When the escape wheel 21 rotates via the first train wheel 20 due to the mechanical energy stored in the mainspring 12, the teeth 211 of the escape wheel 21 push against the pallet stones 221, 222 of the pallet fork 22, causing the stag beetle 223 on the opposite side of the pallet stones 221, 222 of the pallet fork 22 to move left and right, pushing against the impulse jewel 37 of the balance wheel 30 and rotating the balance wheel 31. The impulse jewel 37 is made of a friction-resistant artificial ruby ​​and has the property of trying to stay in the center of the stag beetle 223, but the pallet stones 221, 222 of the pallet fork 22 are pushed by the teeth 211 of the escape wheel 21, causing the stag beetle 223 to move left and right, causing it to oscillate left and right, which causes the balance wheel 31 to rotate left and right, and from the state where it has fully rotated left and right, the balance spring 34 rotates the balance wheel 31 in the opposite direction. 3 and 4, the midpoint of the balance wheel 31, which oscillates by rotating back and forth left and right through an oscillation angle of 280°, is designated as a rotation angle of 0°. Positions of the balance wheel 31 rotated clockwise from this rotation angle of 0° are indicated by positive rotation angles, and positions of the balance wheel 31 rotated counterclockwise are indicated by negative rotation angles. Therefore, in FIG. 3, (A) to (D) show states in which the balance wheel 31 is positioned at rotation angles of -140°, -90°, 70°, and 0°, respectively. Similarly, in FIG. 4, (D) to (G) show states in which the balance wheel 31 is positioned at rotation angles of 0°, +70°, +90°, and +140°, respectively.

[0013] Therefore, in FIG. 3, (A) shows the state in which the balance wheel 31 rotates counterclockwise and stops, and then starts to rotate clockwise due to the balance spring 34. In the state (A), the pallet jewel 222 engages with the teeth 211 of the escape wheel 21, and the pallet fork 22 stops the escape wheel 21. (B) shows the state in which the balance wheel 31 rotates clockwise by +50° from the rotation angle of -140° in (A), resulting in a rotation of -90°. (C) shows the state in which the balance wheel 31 rotates clockwise by +20° from the rotation angle of -90° in (B), resulting in a rotation of -70°. In the states (B) and (C), the impulse jewel 37 has not moved to a position where it abuts the stag beetle 223, so the pallet fork 22 maintains the state in which it stops the escape wheel 21, just like in (A). (D) is the state in which the balance wheel 31 has rotated clockwise by +70° from the rotation angle position of -70° in (C), to a rotation angle position of 0°. Between (C) and (D), the balance wheel 31 rotates clockwise and the impulse jewel 37 hits the stag beetle 223, disengaging the pallet stone 222 from the tooth 211, and the escape wheel 21 rotates by the mainspring 12 and the first train wheel 20. Furthermore, the tip face of the tooth 211 of the escape wheel 21 hits the tip face of the pallet stone 222, causing the escape wheel 21 to operate the pallet fork 22, and the stag beetle 223 of the pallet fork 22 pushes the impulse jewel 37, providing energy to the balance 30.

[0014] In Figure 4, (D) is the same state as (D) in Figure 3. (E) is the state in which the balance wheel 31 has rotated clockwise by +70° from the position of rotation angle 0° in (D), resulting in the balance wheel 31 having rotated to a position of rotation angle +70°. Between (D) and (E), the pallet fork 22 abuts against a dowel pin (not shown) and stops, and the pallet jewel 221 engages with the teeth 211 of the escape wheel 21, stopping the escape wheel 21. (F) is the state in which the balance wheel 31 has rotated +20° clockwise from the rotation angle +70° position in (E) to a rotation angle of +90°. (G) is the state in which the balance wheel 31 has rotated +50° clockwise from the rotation angle +90° position in (F) to a rotation angle of +140°. In the states (F) and (G), the impulse jewel 37 does not hit the stag beetle 223, so like in (E), the pallet fork 22 maintains the state in which it has stopped the escape wheel 21. As a result of the above, the balance wheel 31 rotates clockwise from the -140° position to the +140° position. After that, the balance wheel 31 rotates counterclockwise from the +140° position to the -140° position. After that, the balance wheel 31 oscillates by repeating the above clockwise and counterclockwise rotations. 3 and 4, the first rotor 61 fixed to the balance axle 33 of the balance wheel 31 is magnetized with two poles and rotates integrally with the balance axle 33, i.e., the balance wheel 31. This changes the direction of the magnetic field lines flowing through the stator 62 and the magnetic core 63, generating induced power in the first coil 64.

[0015] 5 is a diagram showing the circuit configuration of movement 10. Movement 10 includes a first coil 64 provided in generator / governor 60 and used for generating electricity and regulating speed, a first charging circuit 40 connected to first coil 64, a control unit 50 serving as a control device, a power storage device 90, a voltage detection unit 93, and an oscillator 95. Control unit 50 includes an oscillation circuit 51, a rotation detection circuit 52, a control circuit 53, and an overcharge prevention circuit 55. The first charging circuit 40, the control unit 50, the power storage device 90, and the voltage detection unit 93 are connected to a first power supply line 91 and a second power supply line 92. In this embodiment, the potential of the first power supply line 91 is VDD, and the potential of the second power supply line 92 is VSS.

[0016] The first charging circuit 40 is a circuit that rectifies the AC current generated by the first coil 64 of the generator governor 60 into DC current, and regulates the speed by applying a short brake by short-circuiting both ends of the first coil 64. Therefore, various rectifier circuits such as step-up rectifier, full-wave rectifier, half-wave rectifier, and transistor rectifier can be used for the first charging circuit 40. In this embodiment, a half-wave rectifier circuit shown in FIG. 6 is used, the details of which will be described later.

[0017] The power storage device 90 stores electrical energy generated by the first coil 64 of the generator governor 60 and rectified by the rectifier circuit of the first charging circuit 40. The electrical energy stored in the power storage device 90 is supplied to the control unit 50, so the power storage device 90 functions as a power supply circuit for the control unit 50. The current consumption of the control unit 50 is approximately 50 nA. For this reason, the power storage device 90 may be a chip-type all-solid-state battery with a capacity of approximately several tens of μAH. An all-solid-state battery does not require a large space and is less susceptible to battery degradation, ensuring long-term reliability. Note that the power storage device 90 is not limited to an all-solid-state battery, and may be configured using a secondary battery, a capacitor, or the like.

[0018] The voltage detection unit 93 detects the voltage of the power storage device 90 and outputs the detection result to the control unit 50. The oscillator 95 is oscillated by the oscillator circuit 51 of the control unit 50 and outputs a clock signal of a predetermined frequency. The oscillator that outputs the clock signal may be a quartz oscillator or a silicon MEMS oscillator. MEMS is an abbreviation for Micro Electro Mechanical Systems, and when a MEMS oscillator is used, it is less accurate than a quartz oscillator but can be made smaller.

[0019] The oscillator circuit 51 divides the oscillation signal output from the vibrator 95 and outputs a reference clock signal Fs of a predetermined frequency to the control circuit 53. The frequency of the reference clock signal Fs is set according to the frequency of the balance 30, which is linked to the speed of the hands, i.e., the rotation period of the first rotor 61 attached to the balance stem 33. For example, if the frequency of the balance 30 is 8 oscillations, the reciprocating rotation period of the first rotor 61 is 4 Hz, and therefore the frequency of the reference clock signal Fs is also set to 4 Hz. For this reason, the oscillator circuit 51 serves as reference signal output means that outputs the reference clock signal Fs, which is a reference signal.

[0020] The rotation detection circuit 52 detects the rotation period of the first rotor 61 and is composed, for example, of a waveform shaping circuit and a monostable multivibrator connected to the first charging circuit 40 of the generator governor 60. The waveform shaping circuit is composed of an amplifier and a comparator and converts the sine wave, which is the electromotive voltage waveform, into a square wave. The monostable multivibrator functions as a bandpass filter that passes only pulses with a certain period or less, and outputs a noise-free rotation detection signal FG1 to the control circuit 53. In other words, the rotation detection circuit 52 outputs the rotation detection signal FG1 based on the electromotive voltage waveform of the first coil 64. Therefore, the rotation detection circuit 52 is a detection means that outputs a detection signal indicative of the oscillations of the balance 30 based on the electromotive voltage generated in the first coil 64, and the rotation detection signal FG1 is a detection signal indicative of the oscillations of the balance 30.

[0021] The control circuit 53 outputs a control signal P1 to the first charging circuit 40 in accordance with the result of comparison between a reference clock signal Fs, which is a reference signal input from the oscillation circuit 51, and a rotation detection signal FG1, which is a detection signal input from the rotation detection circuit 52. Therefore, the control circuit 53 is a control means that outputs the control signal P1 to the first charging circuit 40 in accordance with the result of comparing the detection signal with the reference signal. The control signal P1 is also a chopper signal whose pulse width is variably controlled. When the voltage of the storage device 90 detected by the voltage detection unit 93 becomes equal to or higher than a preset threshold voltage, the overcharge prevention circuit 55 turns off the switch provided on the first power supply line 91 or the second power supply line 92 that charges the storage device 90, thereby preventing overcharging of the storage device 90.

[0022] [1st charging circuit] As shown in FIG. 6, the first charging circuit 40 is a half-wave rectifier circuit, and controls the rotational speed of the first rotor 61 and the balance wheel 31, i.e., the balance 30, via the first coil 64 by shorting out the first coil 64 of the generator governor 60 by chopping. The first charging circuit 40 includes a field-effect transistor 41, a diode 42, and a boost capacitor 43. The boost capacitor 43 is connected between a first power supply line 44 and a second power supply line 45. In this embodiment, the potential of the first power supply line 44 is VDD1, and the potential of the second power supply line 45 is VSS1. Note that the potential VDD1 may be the same as the potential VDD, or may be a different potential. Similarly, the potential VSS1 may be the same as the potential VSS, or may be a different potential. The first terminal MG1 of the first coil 64 is connected to the first power supply line 44. The field-effect transistor 41 is a P-channel field-effect transistor connected between the second terminal MG2 of the first coil 64 and the first power supply line 44, and functions as a switch that disconnects and connects the second terminal MG2 and the first power supply line 44. The gate of the field-effect transistor 41 is connected to the control circuit 53. Therefore, the first charging circuit 40 performs chopping control that intermittently shorts both ends of the first coil 64 by connecting and disconnecting the field-effect transistor 41 in response to a control signal P1 output from the control circuit 53. The diode 42 is disposed between the second terminal MG2 of the first coil 64 and the second power supply line 45. The diode 42 may be any type of unidirectional element that allows current to flow in one direction, and may be, for example, a Schottky barrier diode or a silicon diode.

[0023] The first charging circuit 40 performs chopping control using a control signal P1, which is a chopper signal from the control circuit 53. Chopping control is control that turns the field-effect transistor 41 on and off at a frequency higher than the rotation of the first rotor 61 based on the control signal P1. This control repeatedly shorts and opens both ends of the first coil 64. While the field-effect transistor 41 is on, both ends of the first coil 64 are shorted and in a short state, causing a large current to flow inside the first coil 64. Next, when the field-effect transistor 41 is turned off, the current that was flowing through the field-effect transistor 41 at that moment is converted into voltage, generating a high induced voltage.

[0024] Furthermore, the control of turning on and off both ends of the first coil 64 through chopping control is related to the speed regulation control of the first rotor 61, i.e., the balance wheel 31. Figure 7 shows the control signal P1, which is a brake signal waveform for chopping control. The field-effect transistor 41 is turned on when the control signal P1 is at L level and turned off when it is at H level. Therefore, the period when the control signal P1 is at L level is the brake period, and the ratio of the brake period to one cycle of the control signal P1 is defined as the duty ratio or brake duty. In other words, the brake duty refers to the ratio of the brake period to the cycle of the control signal P1. For example, the control signal P1 in Figure 7 has a chopping period of 256 Hz, and the first half of the signal waveform is a waveform in which the L level period is 80%, i.e., the brake duty is 80%, which performs strong brake control. The second half of the signal waveform of the control signal P1 is a waveform in which the L level period is 30%, i.e., the brake duty is 30%, which performs weak brake control. For this reason, in this embodiment, the chopping control executed by the first charging circuit 40 includes a first brake control that applies a first brake, i.e., a strong brake, to the balance 30, and a second brake control that applies a second brake, i.e., a weak brake with a weaker braking force than the first brake, to the balance 30. The control circuit 53 switches between outputting a control signal P1 for the first brake control with a brake duty of 80%, and a control signal P1 for the second brake control with a brake duty of 30%.

[0025] When the field-effect transistor 41 is turned on by the control signal P1 from the control circuit 53, both ends of the first coil 64 are short-circuited, forming a closed loop. As a result, an electromagnetic force is generated by the current flowing through the first coil 64, and a braking force acts on the first rotor 61. In other words, a short brake is applied to the generator governor 60, and energy is stored in the first coil 64. On the other hand, when the field-effect transistor 41 is turned off by the control signal P1 from the control circuit 53, the generator governor 60 operates and generates electricity, including the energy that was stored in the first coil 64 during short braking, so the electromotive force increases.

[0026] The mechanical timepiece 1 starts by winding the mainspring 12 with the crown 7. That is, when the escape wheel 21 rotates via the first train wheel 20 using the mechanical energy stored in the mainspring 12, the anchor 22 swings left and right, causing the balance wheel 31 of the balance 30 to oscillate left and right, as described with reference to Figures 3 and 4. The oscillation of the balance wheel 31 causes the balance arbour 33 and first rotor 61 to rotate, generating an electromotive force in the first coil 64. The generated electrical energy is stored in the power storage device 90, causing the voltage of the power storage device 90 to rise, starting up systems such as the control unit 50, and the oscillator 95 to operate via the oscillation circuit 51.

[0027] FIG. 8 is a waveform diagram showing the signals and the induced voltage in the first coil 64 during speed regulation control by the control unit 50. When the torque from the mainspring 12 rotates the first train wheel 20, which in turn rotates the balance 30 and first rotor 61, an induced voltage, or coil voltage, is generated in the first coil 64 due to the rotation. This coil voltage changes as the first rotor 61 rotates. In addition, a control signal P1 is output from the control circuit 53 to the field-effect transistor 41 of the first charging circuit 40. When the control signal P1 changes from low to high—when the field-effect transistor 41 is switched from on to off and both ends of the first coil 64 are released from a short-circuited state—an electromotive force due to self-induction is added to the induced voltage, generating a large electromotive force. In FIG. 8, the waveform of the voltage generated by the first charging circuit 40 is shown by a solid line. In FIG. 8, the balance 30 and first rotor 61 rotate at approximately 4 Hz, so the sine-wave generated waveform is also 4 Hz. The chopping frequency of the control signal P1 is 256 Hz. In FIG. 8, the original sine-wave generated waveform without the superimposed chopping pulse is shown by a dotted line. The chopping control described above repeatedly shorts and opens both ends of the first coil 64, generating an induced voltage higher than the sine-wave generated voltage. Voltage boosting through chopping control is control that turns the rectifying field-effect transistor 41 in FIG. 6 on and off at a frequency higher than the rotation of the first rotor 61. This control repeatedly shorts and opens both ends of the first coil 64, which is the generating coil. While the field-effect transistor 41 is on, both ends of the first coil 64 are shorted, causing a large current to flow through the coil. Next, when the field effect transistor 41 is turned OFF, the current flowing through the first coil 64 at that moment is converted into a voltage V based on the following equation 1, and a high induced voltage is generated.

[0028] V=-L×(δi / δt)+d·sinθ·(δθ / δt)-r·i…(1)

[0029] In Equation 1, L is the self-inductance, i is the current flowing through the first coil 64, d is the power generation constant, θ is the rotation angle of the first rotor 61, and r is the internal resistance of the first coil 64. Note that the ON / OFF control of both ends of the first coil 64 by the above-mentioned chopping control is closely related to the speed regulation control (brake control) of the first rotor 61.

[0030] The balance 30, or balance wheel 31, rotates reciprocally, swinging between -140° and +140° as described above. Because the direction of rotation reverses at -140° and +140°, the balance wheel 31 reaches its maximum rotational speed around 0°. Chopper voltage boosting at this timing maximizes the electromotive force, resulting in superior power generation performance. In a watch with an 8-beat frequency, the reference clock signal is 4 Hz, and speed regulation control is performed so that the balance 30 vibrates at 4 Hz. Specifically, when the generated voltage of the first coil 64 exceeds the detection threshold, the control unit 50 performs chopping control, applies the electromagnetic brake, and boosts the chopper voltage. The chopper signal is, for example, 512 Hz or 256 Hz. The balance 30 is pre-adjusted to advance, so that the indicated time advances unless the brake is applied.

[0031] When the rotation detection circuit 52 detects that the terminal voltage of the first coil 64, i.e., the electromotive voltage generated in the first coil 64, is less than a preset detection threshold, it sets the rotation detection signal FG1 output to the control circuit 53 to H level, and when it detects that the coil voltage is equal to or greater than the detection threshold, it sets the rotation detection signal FG1 to L level. Therefore, the control circuit 53 can detect that the first rotor 61 has rotated when the rotation detection signal FG1 changes from H level to L level. In other words, the rotation detection circuit 52, which is a detection means, outputs a detection signal by setting the rotation detection signal FG1 to L level when the magnitude of the electromotive voltage generated in the first coil 64 is equal to or greater than the detection threshold. On the other hand, the reference clock signal Fs output from the oscillator circuit 51 to the control circuit 53 is a signal with a constant frequency, for example, 4 Hz. Therefore, as described above, the control circuit 53 can determine whether the rotation of the first rotor 61, i.e., whether the hour hand 4, minute hand 5, and second hand 6 driven by the first train wheel 20, are running ahead or behind by changing the count value of the up / down counter at the timing when the rotation detection signal FG1 changes from H level to L level and the timing when the reference clock signal Fs changes from H level to L level. In the example of FIG. 8, the control circuit 53 performs the weak brake control shown in FIG. 7 during a period T1 when the rotation detection signal FG1 and the reference clock signal Fs are both H level. The control circuit 53 performs the strong brake control during a period T2 when the reference clock signal Fs is H level and the rotation detection signal FG1 changes from H level to L level until the reference clock signal Fs changes from H level to L level. In other words, the control circuit 53 performs chopping control during a period T2 when the rotation detection signal FG1 output from the rotation detection circuit 52, which serves as detection means, is at L level, i.e., during the period when the detection signal is being output. After T2, the control circuit 53 performs weak braking control during a period T3 from when the reference clock signal Fs is at H level until the rotation detection signal FG1 changes from H level to L level. Thereafter, the control circuit 53 performs the same control as in periods T1 to T3, performs strong braking control during periods T4 and T6, and performs weak braking control during periods T5 and T7.

[0032] FIG. 9 shows an example of measurement data showing the relationship between the generated voltage and the brake duty. It can be seen that the generated voltage increases as the brake duty of the control signal P1 applied to the field-effect transistor 41 increases. This characteristic is due to the following reasons. The current flowing through the first coil 64 at the moment both ends of the first coil 64 are turned off varies depending on the brake-off period, i.e., the brake duty. This current increases as the brake duty increases, and therefore the induced voltage also increases. However, once the brake duty exceeds 90%, this current saturates and the generated voltage does not increase any further. The experimental results shown in FIG. 9 indicate that the highest generated voltage can be achieved with a brake duty of approximately 60% to 90%. Therefore, the first charging circuit 40 connected to the first coil 64 can set the brake duty as the control signal P1 during strong brake control within the range of 60% to 90%, which increases the generated voltage in the first coil 64. For example, chopping control is performed with the control signal P1 having a brake duty of 80% (=0.8).

[0033] [Effects of the first embodiment] According to the first embodiment, in a mechanical timepiece 1 in which the mainspring 12 operates the first train wheel 20 to move the hands and the speed is regulated by the escape wheel 21, anchor 22, and balance 30, the vibration of the balance 30 can be regulated based on the result of comparing the rotation detection signal FG1 that detects the rotation of the balance 30, which is the speed regulator, with the reference clock signal Fs output from the oscillator circuit 51, thereby improving the timekeeping accuracy of the mechanical timepiece 1 to the level of a quartz timepiece. The first charging circuit 40 performs chopping control by intermittently shorting both ends of the first coil 64 based on a control signal P1 input to a field-effect transistor 41 connected to the first coil 64, thereby regulating the oscillation of the balance 30 via the first rotor 61, thereby enabling the regulation and control of the first train wheel 20 of the mechanical timepiece 1. Furthermore, chopping control can increase the electromotive force of the first coil 64, ensuring power generation capacity, making it possible to supply the power necessary for the operation of the control unit 50, which is made up of an IC. This makes it possible to put into practical use a mechanical timepiece 1 in which the speed of the balance 30 is regulated by the first rotor 61 and first coil 64.

[0034] The first charging circuit 40 performs chopper boosting even during weak braking control using the control signal P1, so the amount of energy generated can be increased compared to when chopping control is performed only during strong braking control, and the storage device 90 can be charged efficiently. The control circuit 53 executes strong braking control during the period when the electromotive voltage of the first coil 64 is equal to or greater than the detection threshold, and therefore can execute chopper boosting during the period when the rotation speed of the balance 30 is high and the electromotive voltage is high, thereby enabling the storage device 90 to be charged efficiently.

[0035] [Second embodiment] A mechanical timepiece 1B of the second embodiment will be described with reference to Figures 10 to 13. In the mechanical timepiece 1B of the second embodiment, the same or similar components as those in the first embodiment are given the same reference numerals, and descriptions thereof will be omitted or simplified. 10, the mechanical timepiece 1B has a movement 10B provided with a second generator 70 that is independent of the generator-governor 60 having a first coil 64. The movement 10B includes an automatic winding mechanism 100, a mainspring 12, a first train wheel 20, an escapement and balance wheel 30 consisting of an escape wheel 21 and an anchor 22, the generator-governor 60, a first charging circuit 40, a control unit 50B, an oscillator 95, a second train wheel 110, a second generator 70, a second charging circuit 80, and a power storage device 90.

[0036] The automatic winding mechanism 100 includes an oscillating weight 120 and a winding wheel train 150. 11, the oscillating weight 120 is rotatably mounted on the movement 10B by a rotation shaft 121 formed by a bearing. The oscillating weight 120 has an oscillating weight pinion 122 integrally mounted thereon. The winding wheel train 150 includes an eccentric wheel 160, a pawl lever 170, and a transmission wheel 180. The eccentric wheel 160 includes an eccentric shaft member 161 and an eccentric gear 162 attached to the eccentric shaft member 161. The eccentric shaft member 161 has an eccentric portion that is eccentric with respect to the rotation axis of the eccentric gear 162, and a pawl lever 170 is rotatably attached to this eccentric portion. Eccentric gear 162 meshes with rotary spindle pinion 122 and rotates in conjunction with rotary spindle 120. As a result, the eccentric portion of eccentric shaft member 161 revolves around the rotation axis of eccentric gear 162, and pawl lever 170 attached to the eccentric portion moves back and forth toward and away from transmission wheel 180.

[0037] The pawl lever 170 includes a pull pawl lever portion 171 and a push pawl lever portion 172 that sandwich a transmission gear 181 of the transmission wheel 180 in a plan view. The transmission wheel 180 includes a transmission gear 181 and a transmission pinion 182. The pulling pawl of the pulling pawl lever portion 171 and the pushing pawl of the pushing pawl lever portion 172 engage with the transmission gear 181, and the transmission wheel 180 rotates in one direction in conjunction with the forward and backward movement of the pawl lever 170. The rotation of the transmission wheel 180 is transmitted to the ratchet wheel 15 via the transmission pinion 182, and the rotation of the ratchet wheel 15 winds up the mainspring 12.

[0038] The second generator 70 comprises a magnetic core 71, a second coil 72 wound around the magnetic core 71, a stator 73 connected to both ends of the magnetic core 71, a second rotor 74 arranged in the opening of the stator 73 and magnetized to two poles, and a rotor pinion 75 formed integrally with the second rotor 74. Here, the second coil 72 for power generation and the first coil 64 for speed regulation and power generation are arranged at an angle of approximately 90° to each other in a plan view seen from the front side of the mechanical timepiece 1B. In other words, the angle between the longitudinal direction of the magnetic core 71 around which the second coil 72 is wound and the longitudinal direction of the magnetic core 63 around which the first coil 64 is wound is approximately 90°. The second wheel train 110 transmits the rotation of the oscillating weight 120 to rotate the second rotor 74, and includes a gear 111 that meshes with the rotor pinion 75, and a pinion 112 that meshes with the oscillating weight pinion 122. The second wheel train 110 may be configured by combining multiple gears, as long as it can increase the rotation of the oscillating weight 120 and transmit it to the second rotor 74 for power generation. Rotation of the oscillating weight 120 rotates the second rotor 74 via the second gear train 110, which is, for example, a 100-times speed-increasing gear train. This allows the rotation speed of the second rotor 74 to be as high as, for example, about 100 Hz. The induced electromotive force generated in the second coil 72 increases the amount of change in magnetic flux when the second rotor 74 is rotated at a high speed, and a large electromotive force can be obtained.

[0039] 12 is a diagram showing the circuit configuration of the movement 10B. The movement 10B includes a first coil 64, a first charging circuit 40, a power storage device 90, a voltage detection unit 93, a vibrator 95, a second coil 72, a second charging circuit 80, and a control unit 50B. The first coil 64, the first charging circuit 40, the power storage device 90, the voltage detection unit 93, and the vibrator 95 have the same configurations as those in the first embodiment, and therefore their description will be omitted. The second charging circuit 80 is a circuit connected to the second coil 72 and rectifies the AC current generated by the second coil 72 into DC current. Various rectification circuits, such as step-up rectification, full-wave rectification, half-wave rectification, and transistor rectification, can be used.

[0040] The control unit 50B includes an oscillation circuit 51, a rotation detection circuit 52, a control circuit 53, a power generation detection circuit 54, and an overcharge prevention circuit 55. The oscillation circuit 51, the rotation detection circuit 52, the control circuit 53, and the overcharge prevention circuit 55 have the same configurations as those in the first embodiment, and therefore their description will be omitted. The power generation detection circuit 54 detects the generated voltage of the second generator 70 and is composed of, for example, a comparator connected to the second charging circuit 80 that compares the generated voltage with a threshold voltage. The power generation detection circuit 54 of this embodiment outputs an L-level signal to the control circuit 53 while not detecting power generation, and outputs an H-level signal to the control circuit 53 while detecting power generation.

[0041] Next, the speed regulation control by the control unit 50B will be described with reference to the flowchart of FIG. Control unit 50B executes step S1 to determine whether the voltage of power storage device 90 detected by voltage detection unit 93, i.e., the power supply voltage of control unit 50B, is greater than a predetermined value. Control unit 50B continues step S1 while the determination in step S1 is NO. This is because, if the charging voltage of power storage device 90 is less than the predetermined voltage, vibrator 95 may have stopped oscillating, making stable control impossible.

[0042] If the charging voltage detected by the voltage detection unit 93 becomes equal to or greater than the predetermined voltage and the determination in step S1 is YES, the control unit 50B executes step S2, which is a power generation detection process by the power generation detection circuit 54. Next, the control unit 50B executes step S3, which determines whether or not power generation has been detected by the power generation detection process of step S2. If the determination in step S3 is NO, the control unit 50B executes step S4, in which rotation detection processing is performed by the rotation detection circuit 52. As described above, when the coil voltage generated in the first coil 64 exceeds the detection threshold, the rotation detection circuit 52 determines that rotation of the first rotor 61 has been detected, and changes the rotation detection signal FG1 from H level to L level.

[0043] Next, the control unit 50B executes step S5 of comparing the reference clock signal Fs input from the oscillation circuit 51 with the rotation detection signal FG1, which is the rotation detection result of the first rotor 61 input from the rotation detection circuit 52. In this embodiment, the control circuit 53 has an up-down counter, the up-count input of which receives the rotation detection signal FG1 and the down-count input of which receives the reference clock signal Fs. The up-down counter is, for example, a 4-bit counter, and is initialized to an initial count value of "11" upon system reset or power-on. When the rotation detection signal FG1 changes from H level to L level, the count value of the up-down counter is incremented by 1, and when the reference clock signal Fs changes from H level to L level, the count value of the up-down counter is decremented by 1. If the count value of the up-down counter is greater than the initial count value "11," the control circuit 53 determines the up-down counter to be "leading" in step S5. If the count value of the up-down counter is equal to or less than the initial count value "11," the control circuit 53 determines the up-down counter to be "lagging" in step S5.

[0044] If the control unit 50B detects an advance in the rotation of the first rotor 61 in step S5, it executes strong braking control in step S6. If the control unit 50B detects a delay in the rotation of the first rotor 61 in step S5, it executes weak braking control in step S7. During the strong braking control in step S6, the control circuit 53 outputs a control signal P1 with a brake duty of 80%. Therefore, the brake-on time in the reference period is longer, and strong braking control is performed on the generator governor 60, but because the brake is turned off at regular intervals, chopping control is performed, making it possible to improve the braking torque while maintaining the induced voltage. During weak brake control in step S7, the control circuit 53 outputs a control signal P1 with a brake duty of 30%. Therefore, the brake-on time in the reference cycle is shortened, and the generator governor 60 is hardly braked, i.e., weak brake control is performed. After executing the brake control in step S6 or step S7, the control unit 50B returns to step S1 and continues the control.

[0045] Furthermore, when the control unit 50B determines YES in step S3, it executes fixed brake control in step S8. During the fixed brake control in step S8, the control circuit 53 continues the brake control that was in effect immediately before the transition to fixed brake control. That is, if the immediately preceding brake control was the strong brake control in step S6, the control circuit 53 outputs a control signal P1 with a brake duty of 80% as a fixed chopper signal during the fixed brake control in step S8. Furthermore, if the immediately preceding brake control was the weak brake control in step S7, the control circuit 53 outputs a control signal P1 with a brake duty of 30% as a fixed chopper signal during the fixed brake control in step S8. After executing the fixed brake control in step S8, the control unit 50B returns to step S1 and continues the control. Note that power generation by the second generator 70 is only generated when the wrist wearing the mechanical timepiece 1B is moved, causing the oscillating weight 120 to rotate. Therefore, while the mechanical timepiece 1B is in operation, there are longer periods of time when power is not being generated than when it is. Furthermore, when speed regulation control is based on the reference signal output from the oscillator 95, the primary cause of changes in the accuracy of the mechanical timepiece 1B is variations in the reference signal due to temperature changes. A typical tuning-fork-type quartz oscillator has a quadratic temperature characteristic curve with a peak at approximately 25°C. When worn on the user's wrist, the internal temperature of the watch remains stable at around 25°C, with little change. Therefore, there are almost no problems with accuracy even if speed regulation control is stopped and fixed brake control is used while the watch is being worn.

[0046] [Effects of the second embodiment] In the mechanical timepiece 1B of the second embodiment, the speed of the first coil 64 is regulated and the generated voltage is boosted by chopper boosting, so the same effects as in the first embodiment can be achieved. Furthermore, by providing a second generator 70 and second charging circuit 80 dedicated to power generation in addition to the generator governor 60 and first charging circuit 40, the power generation performance of the mechanical timepiece 1B can be improved. This eliminates the need to increase the size of the first coil 64 and second coil 72, improving the design freedom for the component layout of the movement 10B. Furthermore, by adding the second generator 70, the overall power generation capacity can be increased, and the drive voltage of the ICs constituting the control unit 50B can also be made relatively high. This means that there is no need to use expensive ICs manufactured using special processes with low power consumption as components, and low-cost ICs manufactured using general-purpose processes can be used.

[0047] The mainspring 12 can be wound by the oscillating weight 120 and the winding train wheel 150, and the second generator 70 can be operated by the oscillating weight 120 and the second train wheel 110, so if the user wears the mechanical timepiece 1B on their wrist or the like, the mainspring 12 can be wound automatically and electricity can be generated by the second generator 70. This eliminates the need for the user to manually wind the mainspring 12 or operate the second generator 70, improving convenience. Furthermore, since the second rotor 74 is dedicated to power generation, the speed increase ratio of the second gear train 110, which transmits the rotation of the rotating weight 120 to the second rotor 74, can also be set to a speed increase ratio that can maximize the power generation capacity of the second generator 70, thereby achieving high power generation capacity.

[0048] A power generation detection circuit 54 is provided to detect the power generation state of the second generator 70, and the control circuit 53 executes fixed brake control to stop control of the rotation speed during power generation detection, preventing electromagnetic noise generated during power generation from being mistaken for a rotation detection signal or the like, which would otherwise cause the time indicated by the hands to deviate significantly. Also, since fixed brake control is performed during power generation detection, the rotation speed of the first coil 64 can be appropriately controlled, allowing the hour hand 4, minute hand 5, and second hand 6 to move with almost no deviation from the indicated time.

[0049] In fixed brake control, the control signal P1 with the pulse width immediately before power generation is detected is used for control, so that the speed regulation control immediately before the power generation state is detected can be continued and the rotation speed of the first rotor 61 can be appropriately controlled.

[0050] The first coil 64 of the generator governor 60 and the second coil 72 of the second generator 70 are arranged at an angle of approximately 90° to each other, which weakens the electromagnetic coupling between the first coil 64 and the second coil 72 and prevents electromagnetic noise generated from the second coil 72 during power generation from entering the first coil 64 and causing erroneous detection of rotation. Since a second generator 70 having a second coil 72 and a second rotor 74 is provided as the power generation mechanism, there is no need to provide a translucent synthetic resin dial in order to use a solar panel, and a metal dial can be used, improving the external design of the watch.

[0051] [Third embodiment] A mechanical timepiece 1C of the third embodiment will be described with reference to Figures 14 to 16. In the mechanical timepiece 1C of the third embodiment, the same or similar configurations as those of the first and second embodiments are given the same reference numerals, and descriptions thereof will be omitted or simplified.

[0052] The mechanical timepiece 1C is equipped with a movement 10C shown in Fig. 14. The movement 10C is equipped with a winding wheel train 150C, a mainspring 12, a first wheel train 20, an escapement (escape wheel 21, pallet fork 22) and balance 30, a generator / governor 60, a first charging circuit 40, a control unit 50C, an oscillator 95, a second wheel train 110C, a second generator 70C, a second charging circuit 80, and a power storage device 90. The mainspring 12, the first wheel train 20, the escape wheel 21, the pallet fork 22, the balance 30, the first charging circuit 40, the generator / governor 60, the second charging circuit 80, the power storage device 90, and the oscillator 95 are the same as those in the second embodiment, and therefore description thereof will be omitted.

[0053] The winding wheel train 150C may be equipped with a crown wheel 16 rotated by the crown 7, as in the first embodiment, or may be equipped with an eccentric wheel 160, a pawl lever 170, and a transmission wheel 180 that transmit the rotational torque of the oscillating weight 120, as in the winding wheel train 150 of the second embodiment. 15, the second train wheel 110C includes a first transmission wheel 151 that meshes with the barrel gear 13, and a second transmission wheel 152 that has a pinion that meshes with the first transmission wheel 151. Therefore, the second train wheel 110C accelerates the rotation of the barrel gear 13 and transmits it to the second rotor 74C. The second generator 70C has the same configuration as the second generator 70 of the second embodiment, and includes a magnetic core 71, a second coil 72 wound around the magnetic core 71, a stator 73 connected to both ends of the magnetic core 71, a second rotor 74C arranged in an opening of the stator 73, and a rotor pinion 75 formed integrally with the second rotor 74C and meshing with the second transmission wheel 152. The second rotor 74C uses a six-pole rotor with three north poles and three south poles, which allows for a higher power generation frequency and a larger electromotive force to be obtained compared to when a two-pole rotor is used. Furthermore, the first coil 64 of the generator governor 60 and the second coil 72 of the second generator 70C are disposed on opposite sides of the planar central axis of the movement 10C, and are disposed so that the distance between the coils 64, 72 is as large as possible. The second train wheel 110C accelerates the rotation of the barrel wheel 13 and transmits it to the second rotor 74C, so the rotation speed of the second rotor 74C is lower than that of the second rotor 74 of the second embodiment, and less electromagnetic noise is generated from the second coil 72 during power generation. Furthermore, by increasing the distance between the coils 64, 72, it is possible to prevent erroneous detection caused by the influence of electromagnetic noise generated in the second coil 72 when detecting the rotation of the first rotor 61 based on the electromotive voltage waveform of the first coil 64.

[0054] 16, the control unit 50C includes an oscillator circuit 51, a rotation detection circuit 52, a control circuit 53, and an overcharge prevention circuit 55, similar to the control unit 50 of the first embodiment. The control circuit 53 of the control unit 50C outputs a control signal P1 to the first charging circuit 40 and a second control signal P2 to the second charging circuit 80. The second charging circuit 80, like the first charging circuit 40, is composed of a half-wave rectifier circuit and the like, and performs second chopping control by intermittently shorting both ends of the second coil 72 in response to the second control signal P2. Because the second generator 70C is dedicated to power generation, the second control signal P2 is a pulse signal with a fixed duty that is optimal for power generation. The first charging circuit 40 and the second charging circuit 80 are connected in series to the power storage device 90.

[0055] In the mechanical timepiece 1C, when the barrel gear 13 is rotated by the mainspring 12, the rotation of the barrel gear 13 is transmitted to the escape wheel 21, pallet fork 22, and balance 30 via the first train wheel 20, just like the mechanical timepieces 1 and 1B, and as the first rotor 61 rotates back and forth, electrical energy is generated in the first coil 64, and this electrical energy is rectified via the first charging circuit 40 and charged to the power storage device 90. Also, by performing chopping control using a control signal P1 output from the control circuit 53, the first charging circuit 40 can increase the electromotive force of the first coil 64 and can regulate the rotation of the balance 30, that is, the rotational speed of the first train wheel 20, to the same precision as a quartz timepiece. The rotation of the barrel wheel 13 is amplified via the first transmission wheel 151 and the second transmission wheel 152 and transmitted to the rotor pinion 75 and the second rotor 74C, causing the second rotor 74C to continue rotating in one direction. The control unit 50C outputs a second control signal P2 with a fixed duty cycle optimal for power generation, and the second charging circuit 80 performs second chopping control optimal for power generation. The electrical energy generated in the second coil 72 is rectified via the second charging circuit 80 and charged into the power storage device 90.

[0056] [Effects of the third embodiment] The mechanical timepiece 1C of the third embodiment can also achieve the same effects as the previous embodiments. In addition, a second generator 70C and a second charging circuit 80 are provided for power generation only, and the second charging circuit 80 performs second chopping control using a second control signal P2 with a fixed duty that is optimal for power generation, thereby maximizing power generation performance. Furthermore, since first charging circuit 40 and second charging circuit 80 are connected in series, it is possible to increase the charging voltage of power storage device 90. Therefore, even if small-sized coils are used as first coil 64 and second coil 72, it is possible to ensure the voltage necessary to charge power storage device 90.

[0057] [Variations] The present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention. The first charging circuit 40 is not limited to the configuration of the above embodiment. For example, as shown in a first charging circuit 40D in Fig. 17, a double boost rectifier circuit may be used, in which a diode 46 is provided on the second power supply line 45, a diode 47 is provided between the second power supply line 45 and the first terminal MG11 of the first coil 64, and a boost capacitor 48 is provided between the second power supply line 45 and the second terminal MG12 of the first coil 64. Because the first charging circuit 40D includes the boost capacitor 48, charging efficiency can be improved compared to the half-wave rectifier circuit of the first charging circuit 40, especially when the electromotive voltage in the first coil 64 is low.

[0058] In the above embodiment, the chopping control by the control signal P1 includes strong brake control that performs first brake control and weak brake control that performs second brake control. However, as shown in FIG. 18, the chopping control by the control signal P1 may be such that strong brake control, which is the first brake control, is performed during periods T2, T4, and T6, and brake-off control, in which no brake is applied to the balance 30, is performed during periods T1, T3, T5, and T7. 18, the chopping control executed by the first charging circuit 40 includes first brake control, which applies a first brake, or strong brake, to the balance 30, and brake-off control, which does not apply a brake to the balance 30. The control circuit 53 switches between outputting a control signal P1 for first brake control with a brake duty of 80%, and outputting a control signal P1 for brake-off control, which has an L level period of 0%, i.e., a continuous H level. In this way, by performing chopping control that switches between strong brake control and brake-off control, the balance 30 is not braked during brake-off control, and kinetic energy loss of the balance 30 can be reduced.

[0059] The first rotor 61 is not limited to being fixed to the balance stem 33 of the balance 30, but may be any rotor that rotates in conjunction with the balance 30. For example, the first rotor 61 may be rotated via a wheel train that includes a gear attached to the balance stem 33. The method for detecting the vibration of the balance 30 is not limited to the method of comparing the electromotive force of the first coil 64 with a detection threshold value, and the vibration of the balance 30 may be detected by providing an optical sensor or a magnetic sensor.

[0060] [summary] The mechanical timepiece disclosed herein is characterized by comprising a mainspring, a first train wheel that transmits power from the mainspring, hands that are driven by the first train wheel and display the time, a balance wheel that is driven via the first train wheel, a first rotor that rotates in conjunction with the balance wheel, a first coil that applies braking force to the balance wheel via the first rotor and generates electrical energy, a first charging circuit that executes chopping control that regulates the speed of the balance wheel and boosts the electrical energy generated by the first coil by intermittently short-circuiting both ends of the first coil based on a control signal, control means that outputs the control signal to the first charging circuit, and a power storage device that stores the electrical energy output from the first charging circuit. According to the mechanical timepiece of the present disclosure, the oscillation of the balance can be regulated by intermittently shorting both ends of the first coil, thereby improving the timekeeping accuracy of the mechanical timepiece. Furthermore, by intermittently shorting the first coil using the first charging circuit, the electrical energy generated in the first coil can be boosted, thereby increasing the charging voltage to the power storage device and improving power generation efficiency. Therefore, even if the rotation speed of the first rotor cannot be increased because it rotates in conjunction with the forward and reverse rotation of the balance, the electromotive force of the first coil can be increased, ensuring power generation capacity. This makes it possible to supply the power necessary to operate the control circuit that outputs a control signal to intermittently short-circuit both ends of the first coil, thereby enabling the practical application of a mechanical timepiece in which the balance is regulated by the first rotor and first coil.

[0061] In the mechanical timepiece disclosed herein, it is preferable that the timepiece comprises a detection means for outputting a detection signal indicating the oscillation of the balance wheel based on the electromotive force generated in the first coil, and a reference signal output means for outputting a reference signal, and that the control means outputs the control signal to the first charging circuit depending on the result of comparing the detection signal with the reference signal. According to the mechanical timepiece of the present disclosure, the first charging circuit can regulate the oscillation of the balance by performing chopping control based on a control signal corresponding to the result of comparing a detection signal that detects the oscillation of the balance with a reference signal, so the timekeeping accuracy of the mechanical timepiece can be matched to the reference signal. Therefore, by having the reference signal output means output a reference signal based on a clock signal output from a quartz oscillator or the like, the timekeeping accuracy of the mechanical timepiece can be improved to the level of a quartz timepiece.

[0062] In the mechanical timepiece of the present disclosure, the detection means may output the detection signal when the electromotive voltage is equal to or greater than a detection threshold, and the control means may output the control signal during the period in which the detection signal is being output, causing the first charging circuit to perform the chopping control. According to the mechanical timepiece of the present disclosure, chopping control is performed in the period when the electromotive voltage is higher than the detection threshold in the balance wheel, whose rotation speed changes to perform forward and reverse rotational motion, i.e., during the period when the rotation speed of the balance wheel is fast, so chopper boost can be performed during the period when the electromotive voltage is high, and the power storage device can be charged efficiently.

[0063] In the mechanical timepiece of the present disclosure, it is preferable that the chopping control includes a first brake control that applies a first brake to the balance wheel, and a second brake control that applies a second brake with a braking force weaker than the first brake, and that the control means switch between and output a control signal for the first brake control and a control signal for the second brake control. According to the mechanical timepiece of the present disclosure, chopping control is performed not only during the period of first brake control in which a first brake with strong braking force is applied, but also during second brake control in which a second brake with weaker braking force than the first brake is applied, thereby increasing the amount of energy generated in the first coil and enabling efficient charging of the power storage device.

[0064] In the mechanical timepiece of the present disclosure, the chopping control may include a first brake control that applies a first brake to the balance wheel, and a brake-off control that does not apply a brake to the balance wheel, and the control means may switch between outputting a control signal for the first brake control and a control signal for the brake-off control. According to the mechanical timepiece of the present disclosure, the balance is not braked during brake-off control, so the loss of kinetic energy in the balance can be reduced.

[0065] In the mechanical timepiece disclosed herein, it is preferable to have a second train wheel, a second rotor that rotates in conjunction with the second train wheel, a second coil that generates the electrical energy through the rotation of the second rotor, and a second charging circuit that charges the electrical energy generated by the second coil to the power storage device. According to the mechanical timepiece of the present disclosure, in addition to the first rotor and first coil for power generation and balance wheel speed regulation, a second rotor and second coil dedicated to power generation are provided, so power can be generated by two generators: a generator speed regulator with the first coil, and a second generator with the second coil, improving power generation performance. Furthermore, since two coils are provided for power generation, the first coil and second coil can be made smaller than when power is generated by only one coil, making it easier to arrange each coil within the movement and increasing the degree of freedom in designing the layout of the movement.

[0066] In the mechanical timepiece of the present disclosure, it is preferable that the timepiece has a winding mechanism that winds the mainspring, and the second train wheel accelerates the movement of the winding mechanism and transmits it to the second rotor. According to the mechanical timepiece of the present disclosure, the second wheel train accelerates the movement of the winding mechanism, such as the oscillating weight that winds the mainspring, and transmits it to the second rotor. This allows the rotational speed of the second rotor to be increased compared to the first rotor used to regulate the balance, and also improves the electromotive force of the second coil, allowing the power storage device to be charged efficiently.

[0067] In the mechanical timepiece of the present disclosure, it is preferable that the second train wheel amplifies the movement of the mainspring and transmits it to the second rotor, and the second charging circuit performs second chopping control that intermittently short-circuits both ends of the second coil. According to the mechanical timepiece of the present disclosure, even though the rotational speed of the second rotor is somewhat restricted due to linkage with the movement of the mainspring, second chopping control is performed to intermittently short-circuit the terminals of the second coil, so the electromotive force in the second coil can be increased by chopper boosting, allowing the power storage device to be charged efficiently. [Explanation of symbols]

[0068] 1...mechanical watch, 1B...mechanical watch, 1C...mechanical watch, 10...movement, 10B...movement, 10C...movement, 11...barrel, 12...mainspring, 13...barrel gear, 20...first wheel train, 21...escape wheel, 22...anchor, 30...balance, 31...balance wheel, 33...balance stem, 34...hairspring, 37...impulse jewel, 40...first charging circuit, 40D...first charging circuit, 41...field effect transistor, 50...control unit, 50B...control unit, 50C...control unit, 51...oscillating Oscillating circuit, 52...rotation detection circuit, 53...control circuit, 54...power generation detection circuit, 55...overcharge prevention circuit, 60...power generation governor, 61...first rotor, 64...first coil, 70...second generator, 70C...second generator, 72...second coil, 74...second rotor, 74C...second rotor, 80...second charging circuit, 90...storage device, 100...automatic winding mechanism, 110...second wheel train, 110C...second wheel train, 150...winding wheel train, 150C...winding wheel train, P1...control signal, P2...second control signal.

Claims

1. Spring and a first train wheel that transmits power from the mainspring; a hand driven by the first train wheel to display the time; a balance driven via the first train wheel; a first rotor that rotates in conjunction with the balance; a first coil that applies a braking force to the balance via the first rotor and generates electrical energy; a first charging circuit that executes chopping control to regulate the speed of the balance and boost the electrical energy generated by the first coil by intermittently shorting both ends of the first coil based on a control signal; a control means for outputting the control signal to the first charging circuit; a power storage device that stores the electrical energy output from the first charging circuit; A mechanical watch comprising:

2. 2. The mechanical timepiece according to claim 1, detection means for outputting a detection signal indicative of the oscillation of the balance wheel based on the electromotive voltage generated in the first coil; a reference signal output means for outputting a reference signal; The control means outputs the control signal to the first charging circuit in accordance with a result of comparing the detection signal with the reference signal. A mechanical watch characterized by

3. 3. The mechanical timepiece according to claim 2, the detecting means outputs the detection signal when the electromotive voltage is equal to or greater than a detection threshold value; The control means outputs the control signal during the period in which the detection signal is being output, and causes the first charging circuit to perform the chopping control. A mechanical watch characterized by

4. 2. The mechanical timepiece according to claim 1, the chopping control includes a first brake control for applying a first brake to the balance and a second brake control for applying a second brake having a braking force weaker than that of the first brake, The control means switches between a control signal for controlling the first brake and a control signal for controlling the second brake and outputs the switched signal. A mechanical watch characterized by

5. 2. The mechanical timepiece according to claim 1, the chopping control includes a first brake control that applies a first brake to the balance, and a brake-off control that does not apply a brake to the balance, The control means switches between a control signal for first brake control and a control signal for brake-off control and outputs the switched signal. A mechanical watch characterized by

6. 2. The mechanical timepiece according to claim 1, A second gear train; a second rotor that rotates in conjunction with the second train wheel; a second coil that generates the electrical energy by rotation of the second rotor; a second charging circuit that charges the power storage device with the electrical energy generated by the second coil; A mechanical watch comprising:

7. 7. The mechanical timepiece according to claim 6, a winding mechanism for winding the mainspring, A mechanical timepiece characterized in that the second train wheel accelerates the movement of the winding mechanism and transmits it to the second rotor.

8. 7. The mechanical timepiece according to claim 6, the second gear train amplifies the movement of the mainspring and transmits it to the second rotor; The mechanical timepiece is characterized in that the second charging circuit performs second chopping control to intermittently short-circuit both ends of the second coil.

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