Provided is a radio-controlled timepiece that can reduce overall power consumption. The radio-controlled timepiece 1 has a receiver circuit 12 that executes during a specific time limit a reception process to acquire multiple time data from the standard time signals at different times; storage 22 that stores multiple time data; a timekeeper 23 that keeps an internal time; a time setting adjuster 24 that corrects the internal time based on coherent time data when the number of coherent time data, which is time data that is mutually coherent, in the multiple time data reaches a threshold; and a reception controller 21 that extends the time limit when the number of coherent time data is less than the threshold when a specific time that is shorter than the time limit has past since the reception process started.

Provided is a radio-controlled timepiece that can reduce overall power consumption. The radio-controlled timepiece 1 has a receiver circuit 12 that executes during a specific time limit a reception process to acquire multiple time data from the standard time signals at different times; storage 22 that stores multiple time data; a timekeeper 23 that keeps an internal time; a time setting adjuster 24 that corrects the internal time based on coherent time data when the number of coherent time data, which is time data that is mutually coherent, in the multiple time data reaches a threshold; and a reception controller 21 that extends the time limit when the number of coherent time data is less than the threshold when a specific time that is shorter than the time limit has past since the reception process started.

An electronic watch includes a GPS receiver, a first time correction unit configured to correct time using the time information received by the GPS receiver, a beacon receiver configured to receive a beacon signal containing beacon identification information transmitted from a beacon installed indoors, a first storage unit configured to store beacon identification information and time difference information corresponding to the beacon identification information, a second time correction unit configured to correct a time difference using the beacon signal received by the beacon receiver and the time difference information stored in the first storage unit, and a button configured to accept a reception instruction of the beacon signal, which is operated by an operator. The beacon receiver is configured to receive a beacon signal when the button accepts the reception instruction.

This disclosure relates to systems and methods for verification of time sources. In various embodiments, one or more secondary time sources may be used to verify the accuracy of a primary time source prior to relying on a time signal created by the primary time source. In one embodiment, a first interface is configured to receive the primary time signal from a primary time source, and a second interface in communication with a secondary time source is configured to receive a secondary time signal. A time assessment subsystem is configured to determine an occurrence of a verification criteria. Upon the occurrence of the verification criteria, the system may compare the primary time signal and the secondary time signal to determine whether that the primary time signal is consistent with the secondary time signal. If the signal is consistent, the primary time source may be utilized by the system.

A radio-controlled timepiece includes a first oscillating unit configured to oscillate at a first frequency and output a clock signal, a receiving unit including a second oscillating unit and configured to receive radio waves including time information, frequency of the second oscillating unit being less temperature-dependent than that of the first oscillating unit and the second oscillating unit being configured to oscillate at a second frequency and output a clock signal, a control unit configured to calculate temperature compensation data for the first oscillating unit based on an oscillation frequency of the first oscillating unit obtained using, as a reference, the clock signal output from the second oscillating unit and on the temperature data acquired by a temperature acquiring unit, and a storage unit configured to store the temperature compensation data. The control unit performs temperature compensation for the first oscillating unit based on the temperature compensation data and the temperature data.

A radio-controlled timepiece includes a first oscillating unit configured to oscillate at a first frequency and output a clock signal, a receiving unit including a second oscillating unit and configured to receive radio waves including time information, frequency of the second oscillating unit being less temperature-dependent than that of the first oscillating unit and the second oscillating unit being configured to oscillate at a second frequency and output a clock signal, a control unit configured to calculate temperature compensation data for the first oscillating unit based on an oscillation frequency of the first oscillating unit obtained using, as a reference, the clock signal output from the second oscillating unit and on the temperature data acquired by a temperature acquiring unit, and a storage unit configured to store the temperature compensation data. The control unit performs temperature compensation for the first oscillating unit based on the temperature compensation data and the temperature data.

A processor controls an oscillation circuit such that a frequency of a clock signal is close to a reference frequency based on a frequency of a carrier wave of a standard radio wave and the frequency of the clock signal. In this manner, since the processor controls the frequency of the clock signal by using the carrier wave of the standard radio wave of which the frequency is managed with high accuracy, it becomes possible to improve accuracy of an internal time.

This disclosure relates to systems and methods for verification of time sources. In various embodiments, one or more secondary time sources may be used to verify the accuracy of a primary time source prior to relying on a time signal created by the primary time source. In one embodiment, a first interface is configured to receive the primary time signal from a primary time source, and a second interface in communication with a secondary time source is configured to receive a secondary time signal. A time assessment subsystem is configured to determine an occurrence of a verification criteria. Upon the occurrence of the verification criteria, the system may compare the primary time signal and the secondary time signal to determine whether that the primary time signal is consistent with the secondary time signal. If the signal is consistent, the primary time source may be utilized by the system.

A time information receiver that receives a standard radio wave containing a time code and analyzes the time code based on a demodulated signal of the standard radio wave includes a falling edge cycle measurement part that measures a falling edge cycle of the demodulated signal over a measurement period set in advance and counts an occurrence in which the falling edge cycle is determined to coincide with any of 400 ms, 700 ms, 1300 ms, and 1600 ms, a low level width measurement part that measures a low level width over the measurement period whenever the falling edge cycle of the demodulated signal occurs and counts an occurrence in which the measured low level width is greater than or equal to a predetermined threshold greater than 300 ms but smaller than 500 ms.

A time information receiver that receives a standard radio wave containing a time code and analyzes the time code based on a demodulated signal of the standard radio wave includes a falling edge cycle measurement part that measures a falling edge cycle of the demodulated signal over a measurement period set in advance and counts an occurrence in which the falling edge cycle is determined to coincide with any of 400 ms, 700 ms, 1300 ms, and 1600 ms, a low level width measurement part that measures a low level width over the measurement period whenever the falling edge cycle of the demodulated signal occurs and counts an occurrence in which the measured low level width is greater than or equal to a predetermined threshold greater than 300 ms but smaller than 500 ms.