Mechanical Watch

Patent metadata

Field	Value
Publication number	US-2024272588-A1
Application number	US-202418436138-A
Country	US
Kind code	A1
Filing date	Feb 8, 2024
Priority date	Feb 9, 2023
Publication date	Aug 15, 2024
Grant date	—

Abstract

A mechanical watch includes a balance, an oscillation circuit configured to output a clock signal, a vibration detection unit configured to detect a vibration of the balance and output a vibration detection signal, a speed governing unit including a permanent magnet and a coil, a speed governing control unit, a storage unit configured to store an electrical energy, and a generator. One of the permanent magnet and the coil is held by the balance. The speed governing control unit compares the clock signal and the vibration detection signal and performs the speed governing control of the balance by exerting an electromagnetic force on the permanent magnet, the electromagnetic force being generated by outputting a current to the coil. When a stored energy amount is equal to or smaller than a predetermined value, the speed governing control unit switches a state to a stop state where the speed governing control of the balance is stopped.

First claim

What is claimed is:

1 . A mechanical watch comprising:
a spiral spring; a balance configured to be driven by power from the spiral spring; an oscillation circuit configured to output a clock signal; a vibration detection unit configured to detect a vibration of the balance and output a vibration detection signal; a speed governing unit including a permanent magnet and a coil; a speed governing control unit configured to control the speed governing unit to perform a speed governing control of the balance; a storage unit configured to store an electrical energy to be supplied to the speed governing control unit; and a generator configured to generate the electrical energy, wherein one of the permanent magnet and the coil is held by the balance, the speed governing control unit compares the clock signal and the vibration detection signal and performs the speed governing control of the balance by exerting an electromagnetic force on the permanent magnet, the electromagnetic force being generated by outputting a current to the coil, and when a stored energy amount of the storage unit is equal to or smaller than a predetermined value, the speed governing control unit switches a state to a stop state where the speed governing control of the balance is stopped.

2 . The mechanical watch according to claim 1 , further comprising
a power switch coupled between the coil and a power-source line configured to supply a current to the coil, wherein the speed governing control unit switches the state to the stop state by turning the power switch off.

3 . The mechanical watch according to claim 2 , wherein
the power-source line includes a first power-source line, and a second power-source line of a potential different from that of the first power-source line, the power switch includes:
a first switch coupled between a first terminal of the coil and the first power-source line,
a second switch coupled between a second terminal of the coil and the first power-source line,
a third switch coupled between the first terminal of the coil and the second power-source line, and
a fourth switch coupled between the second terminal of the coil and the second power-source line, and
the speed governing control unit performs a control by switching between a speed governing state and the stop state, the speed governing state being a state where a speed of the balance is governed by controlling on and off of the first switch, the second switch, the third switch, and the fourth switch to control a direction of a current flowing through the coil, the stop state being a state where the first switch, the second switch, the third switch, and the fourth switch are controlled off and no current flows through the coil.

4 . The mechanical watch according to claim 3 , wherein
the vibration detection unit includes:
the coil, and
a detection circuit coupled to the first terminal and the second terminal of the coil, and configured to detect a current flowing through the coil by the permanent magnet moving relative to the coil along with a vibration of the balance and
the speed governing control unit performs a control by switching among a vibration detection state, the speed governing state, and the stop state, the vibration detection state being a state where one of the first switch and the second switch is turned on, and the other of the first switch and the second switch, the third switch, and the fourth switch are turned off, the speed governing state being a state where one of the first switch and the second switch and one of the third switch and the fourth switch are turned on, and the other of the first switch and the second switch and the other of the third switch and the fourth switch are turned off, the stop state being a state where the first switch, the second switch, the third switch, and the fourth switch are turned off.

5 . The mechanical watch according to claim 1 , wherein
the generator is an electromagnetic generator including the permanent magnet and the coil and configured to generate power through a relative movement of the permanent magnet and the coil along with a vibration of the balance.

6 . The mechanical watch according to claim 1 , wherein
the generator is a solar generator including a solar panel.

7 . The mechanical watch according to claim 6 , further comprising
a light-transmitting case back, wherein the solar panel generates power by receiving light transmitted through the case back.

8 . The mechanical watch according to claim 1 , wherein
the generator is an electromagnetic generator including a power generation coil, a rotor, and a rotating mechanism configured to rotate the rotor.

9 . The mechanical watch according to claim 1 , wherein
the generator includes a power generation coil configured to generate power through electromagnetic induction with a magnetic field applied from outside.

Assignees

• Seiko Epson Corp

Inventors

• Fujisawa Teruhiko

Classifications

• G04B17/20

  Compensation of mechanisms for stabilising frequency · CPC title

• G04C3/064 Primary

  the balance controlling indirectly, i.e. without mechanical connection, contacts, e.g. by magnetic or optic means · CPC title

• G04C3/06

  using electromagnetic coupling between electric power source and balance · CPC title

• G04C3/04 Primary

  wherein movement is regulated by a balance · CPC title

• G04C10/02

  the power supply being a radioactive {or photovoltaic} source · CPC title