Electronically controlled mechanical timepiece, control method of an electronically controlled mechanical timepiece, and electronic timepiece
View Patent ↗Provided are a timepiece having a temperature compensator drivable by a low voltage with low current consumption, and a control method of a timepiece. The timepiece includes an arithmetic circuit, a first switch that controls connection of a temperature compensation table storage to a power supply circuit, and a second switch that controls connection of a device-difference compensation data storage to the power supply circuit. The arithmetic circuit calculates a compensation amount based on a temperature measured by a temperature detector, a temperature compensation data, a device-difference compensation data, and outputs to a frequency adjustment control circuit and a theoretical regulation circuit. The first switch is controlled to the connect state during a first power supply connection period including a temperature compensation data read period. The second switch is controlled to the connect state during a second power supply connection period including a device-difference compensation data read period.
1. An electronically controlled mechanical timepiece comprising:
a mechanical energy source;
a generator including a rotor driven by the mechanical energy source;
a power supply circuit configured to store electrical energy generated by the generator;
an energy transfer mechanism configured to transfer torque from the mechanical energy source to the rotor;
a time display device connected to the energy transfer mechanism and configured to display time;
a crystal oscillator; and
a rotation controller configured to control rotation of the rotor and including:
an oscillation circuit that causes the crystal oscillator to oscillate,
a frequency divider that frequency divides an oscillation signal output from the oscillation circuit and outputs a reference signal,
a temperature compensator configured to compensate for variation in the reference signal due to temperature,
a rotation detection circuit configured to measure the rotational frequency of the rotor, and
a brake control circuit configured to control braking the rotor according to a difference between the rotational frequency of the rotor and a frequency of the reference signal;
the temperature compensator including
a frequency adjustment control circuit configured to control the oscillation circuit,
a theoretical regulation circuit configured to control the frequency divider,
a temperature detector configured to measure temperature,
an arithmetic circuit,
temperature compensation table storage in which temperature compensation data common to another electronically controlled mechanical timepiece is stored,
device-difference compensation data storage in which device-difference compensation data based on a characteristic of the crystal oscillator is stored,
a first switch configured to control connection and disconnection of the temperature compensation table storage to the power supply circuit, and
a second switch configured to control connection and disconnection of the device-difference compensation data storage to the power supply circuit;
the arithmetic circuit configured to calculate a compensation amount based on a measured temperature detected by the temperature detector, the temperature compensation data, and the device-difference compensation data, and output to the frequency adjustment control circuit and the theoretical regulation circuit;
the first switch controlled to a connect state during a first power supply connection period including a temperature compensation data read period when the temperature compensation data is read from the temperature compensation table storage, and to a disconnect state when not in the first power supply connection period; and
the second switch controlled to a connect state during a second power supply connection period including a device-difference compensation data read period when the device-difference compensation data is read from the device-difference compensation data storage, and to a disconnect state when not in the second power supply connection period.
2. The electronically controlled mechanical timepiece described in claim 1 , wherein:
the rotation controller includes a constant voltage circuit;
the oscillation circuit, frequency divider, brake control circuit, temperature compensator, frequency adjustment control circuit, arithmetic circuit, and temperature detector are driven by a constant voltage output from the constant voltage circuit; and
the temperature compensation table storage and device-difference compensation data storage are driven by a power source other than the constant voltage circuit.
3. The electronically controlled mechanical timepiece described in claim 1 , wherein:
the temperature measurement period when the temperature detector operates, the temperature compensation data read period, and the device-difference compensation data read period are set to different times.
4. The electronically controlled mechanical timepiece described in claim 1 , wherein:
the rotation controller is configured by an IC manufactured in an SOI process; and
the device-difference compensation data storage is configured by FAMOS.
5. The electronically controlled mechanical timepiece described in claim 1 , wherein:
the temperature detector is configured by a RC oscillator circuit driven by a constant current.
6. A control method of an electronically controlled mechanical timepiece including a mechanical energy source;
a generator including a rotor driven by the mechanical energy source;
a power supply circuit configured to store electrical energy generated by the generator;
an energy transfer mechanism configured to transfer torque from the mechanical energy source to the rotor;
a time display device connected to the energy transfer mechanism and configured to display time;
a crystal oscillator; and
a rotation controller configured to control rotation of the rotor and including
an oscillation circuit that causes the crystal oscillator to oscillate,
a frequency divider that frequency divides an oscillation signal output from the oscillation circuit and outputs a reference signal,
a temperature compensator configured to compensate for variation in the reference signal due to temperature,
a rotation detection circuit configured to measure the rotational frequency of the rotor, and
a brake control circuit configured to control braking the rotor according to a difference between the rotational frequency of the rotor and a frequency of the reference signal;
the temperature compensator including a temperature detector configured to measure temperature,
temperature compensation table storage in which temperature compensation data common to electronically controlled mechanical timepieces is stored,
device-difference compensation data storage in which device-difference compensation data specific to an electronically controlled mechanical timepiece is stored,
a first switch configured to control connection and disconnection of the temperature compensation table storage to the power supply circuit, and
a second switch configured to control connection and disconnection of the device-difference compensation data storage to the power supply circuit;
the control method comprising:
a step of operating the temperature detector to measure temperature;
a step of setting the first switch to a connect state, reading the temperature compensation data from the temperature compensation table storage, and setting the first switch to a disconnect state;
a step of setting the second switch to a connect state, reading the device-difference compensation data from the device-difference compensation data storage, and setting the second switch to a disconnect state;
a step of calculating a compensation amount based on a measured temperature, the temperature compensation data, and the device-difference compensation data;
a step of controlling the oscillation circuit according to the compensation; and
a step of controlling the frequency divider according to the compensation.
7. An electronic timepiece comprising:
a time display device configured to display time;
a crystal oscillator;
a power supply circuit;
an oscillation circuit that causes the crystal oscillator to oscillate;
a frequency divider that frequency divides an oscillation signal output from the oscillation circuit and outputs a reference signal; and
a temperature compensator configured to compensate for variation in the reference signal due to temperature, and including
a frequency adjustment control circuit configured to control the oscillation circuit,
a theoretical regulation circuit configured to control the frequency divider,
a temperature detector configured to measure temperature,
an arithmetic circuit,
temperature compensation table storage in which temperature compensation data common to another electronic timepiece is stored,
device-difference compensation data storage in which device-difference compensation data based on a characteristic of the crystal oscillator is stored,
a first switch configured to control connection and disconnection of the temperature compensation table storage to the power supply circuit, and
a second switch configured to control connection and disconnection of the device-difference compensation data storage to the power supply circuit;
the arithmetic circuit configured to calculate a compensation amount based on a measured temperature detected by the temperature detector, the temperature compensation data, and the device-difference compensation data, and output to the frequency adjustment control circuit and the theoretical regulation circuit;
the first switch controlled to a connect state during a first power supply connection period including a temperature compensation data read period when at least the temperature compensation data is read from the temperature compensation table storage, and to a disconnect state when not in the first power supply connection period; and
the second switch controlled to a connect state during a second power supply connection period including a device-difference compensation data read period when at least the device-difference compensation data is read from the device-difference compensation data storage, and to a disconnect state when not in the second power supply connection period.
8. The electronic timepiece described in claim 7 , further comprising:
a constant voltage circuit that drives the oscillation circuit by a constant voltage;
the temperature compensation table storage and device-difference compensation data storage being driven by a power source other than the constant voltage circuit.