An electronically controlled mechanical timepiece includes: a rotor including a rotary shaft, a pinion that is provided on the rotary shaft and to which torque from a mainspring is transmitted, and a rotor magnet attached to the rotary shaft, the rotor being configured to rotate by the torque; a generator that includes a coil and a stator and that is configured to generate power by rotation of the rotor; a main plate that contains a magnetic material, that has an opposing surface opposed to the stator, and that is configured to support the rotary shaft of the rotor; wherein in a cross-sectional view viewed from a direction perpendicular to an axial direction of the rotary shaft, a center of the stator along the axial direction is disposed farther toward the opposing surface side than a center of the rotor magnet along the axial direction.

An electronically controlled mechanical timepiece includes: a rotor including a rotary shaft, a pinion that is provided on the rotary shaft and to which torque from a mainspring is transmitted, and a rotor magnet attached to the rotary shaft, the rotor being configured to rotate by the torque; a generator that includes a coil and a stator and that is configured to generate power by rotation of the rotor; a main plate that contains a magnetic material, that has an opposing surface opposed to the stator, and that is configured to support the rotary shaft of the rotor; wherein in a cross-sectional view viewed from a direction perpendicular to an axial direction of the rotary shaft, a center of the stator along the axial direction is disposed farther toward the opposing surface side than a center of the rotor magnet along the axial direction.

A power reserve indicator mechanism is for displaying the power reserve of an energy storage of a timepiece movement, powered in a winding phase by an input wheel actuated by a winding-stem or an automatic winding mechanism of the movement, or by an external winder, and arranged to restore energy in the unwinding phase via an output wheel. The power reserve indicator mechanism includes at least one display wheel set indirectly driven by the input wheel or by the output wheel, via a differential mechanism of which the input wheel and the output wheel constitute two inputs, and, at a single output, an output wheel set directly or indirectly driving the display wheel set.

A power reserve indicator mechanism is for displaying the power reserve of an energy storage of a timepiece movement, powered in a winding phase by an input wheel actuated by a winding-stem or an automatic winding mechanism of the movement, or by an external winder, and arranged to restore energy in the unwinding phase via an output wheel. The power reserve indicator mechanism includes at least one display wheel set indirectly driven by the input wheel or by the output wheel, via a differential mechanism of which the input wheel and the output wheel constitute two inputs, and, at a single output, an output wheel set directly or indirectly driving the display wheel set.

A method for producing a timepiece spring includes a step for producing, by casting, a metallic glass raw material constituted of a metallic glass; a step for heating the metallic glass raw material to achieve a superplastic state; and a step for rolling the metallic glass raw material in a superplastic state to produce a sheet material. A timepiece spring is characterized by being obtained by the method for producing a timepiece spring.

A method for producing a timepiece spring includes a step for producing, by casting, a metallic glass raw material constituted of a metallic glass; a step for heating the metallic glass raw material to achieve a superplastic state; and a step for rolling the metallic glass raw material in a superplastic state to produce a sheet material. A timepiece spring is characterized by being obtained by the method for producing a timepiece spring.

A chronograph mechanism includes an energy accumulator, a regulating system, and a gear train connecting the energy accumulator to the regulating system. The energy accumulator is formed by a strip-spring and includes a device for driving the gear train arranged to regulate the torque delivered by the strip-spring.

A chronograph mechanism includes an energy accumulator, a regulating system, and a gear train connecting the energy accumulator to the regulating system. The energy accumulator is formed by a strip-spring and includes a device for driving the gear train arranged to regulate the torque delivered by the strip-spring.

A watch includes a chargeable power supply, a crystal oscillation circuit including a crystal oscillator and an oscillation circuit and configured to stop oscillating when a power supply voltage falls below an oscillation stop voltage and to start oscillating when the power supply voltage exceeds an oscillation start voltage, which is higher than the oscillation stop voltage, and a divider circuit that outputs a reference signal by dividing an oscillation signal output from the oscillation circuit. The watch also includes a temperature compensation circuit that performs a temperature compensation function operation that compensates for variation of the reference signal due to a temperature, a first voltage detection circuit that detects that the power supply voltage exceeded a first voltage that is set higher than the oscillation start voltage, and a control circuit that starts the temperature compensation function operation of the temperature compensation circuit when the first voltage detection circuit detects that the power supply voltage exceeded the first voltage, and subsequently continues the temperature compensation function operation even when the power supply voltage falls below the first voltage.

A watch includes a chargeable power supply, a crystal oscillation circuit including a crystal oscillator and an oscillation circuit and configured to stop oscillating when a power supply voltage falls below an oscillation stop voltage and to start oscillating when the power supply voltage exceeds an oscillation start voltage, which is higher than the oscillation stop voltage, and a divider circuit that outputs a reference signal by dividing an oscillation signal output from the oscillation circuit. The watch also includes a temperature compensation circuit that performs a temperature compensation function operation that compensates for variation of the reference signal due to a temperature, a first voltage detection circuit that detects that the power supply voltage exceeded a first voltage that is set higher than the oscillation start voltage, and a control circuit that starts the temperature compensation function operation of the temperature compensation circuit when the first voltage detection circuit detects that the power supply voltage exceeded the first voltage, and subsequently continues the temperature compensation function operation even when the power supply voltage falls below the first voltage.