Abstract: Provided is a satellite radio-controlled watch, which is capable of holding back a receiving operation when in a posture that does not allow normal reception of a satellite signal, and is capable of performing a receiving operation under conditions varied to suit the type of reference information to be obtained. The satellite radio-controlled watch includes: a reception circuit (31) for receiving a satellite signal; and a controller (47) for sequentially detecting a received light amount of the satellite radio-controlled watch, calculating a received light variation which is an amount of change of the received light amount, and controlling the reception circuit (31) to start an operation of receiving the satellite signal, based on the received light variation.

Abstract: A radio-controlled wristwatch that determines whether or not illuminance of light irradiating a solar cell is high, using plural criteria but without directly measuring voltage or current. The wristwatch includes: a solar cell; a control circuit which stops operation under a predetermined condition; and an illuminance detection circuit which indicates illuminance of light irradiating the solar cell being higher than a given threshold value. The wristwatch switches the given threshold value between a first and a second value, larger than the first value, starts the control circuit in a stop state when a signal indicating that the illuminance is higher than the first value is output, receives a satellite signal containing time information from a satellite when a signal indicating that the illuminance is higher than the second value is output, and displays time corresponding to the time information contained in the received satellite signal.

Abstract: Provided is a radio-controlled wristwatch that receives a radio wave including day-related information from a satellite within a global positioning system, in which a cycle number of the day-related information is correctly updated even in a case where a power supply voltage drops.

Abstract: Provided is a radio-controlled watch capable of performing leap second correction even when information on a leap second is not received from a satellite. Provided is a radio-controlled watch that adjusts time by receiving a signal containing time information from a satellite, the radio-controlled watch being configured to: store a leap second correction value to be used for leap second correction with respect to the time information; display a numerical value corresponding to the leap second correction value; receive an instruction operation of changing the leap second correction value from a user in a state in which the numerical value is displayed; and change the leap second correction value in response to the received instruction operation.

Abstract: Provided is a radio-controlled wristwatch that receives a radio wave including day-related information from a satellite within a global positioning system, in which a cycle number of the day-related information is correctly updated even in a case where a power supply voltage drops.

Abstract: A radio-controlled wristwatch that determines whether or not illuminance of light irradiating a solar cell is high, using plural criteria but without directly measuring voltage or current. The wristwatch includes: a solar cell; a control circuit which stops operation under a predetermined condition; and an illuminance detection circuit which indicates illuminance of light irradiating the solar cell being higher than a given threshold value. The wristwatch switches the given threshold value between a first and a second value, larger than the first value, starts the control circuit in a stop state when a signal indicating that the illuminance is higher than the first value is output, receives a satellite signal containing time information from a satellite when a signal indicating that the illuminance is higher than the second value is output, and displays time corresponding to the time information contained in the received satellite signal.

Abstract: Provided is a satellite radio-controlled watch, which is capable of holding back a receiving operation when in a posture that does not allow normal reception of a satellite signal, and is capable of performing a receiving operation under conditions varied to suit the type of reference information to be obtained. The satellite radio-controlled watch includes: a reception circuit (31) for receiving a satellite signal; and a controller (47) for sequentially detecting a received light amount of the satellite radio-controlled watch, calculating a received light variation which is an amount of change of the received light amount, and controlling the reception circuit (31) to start an operation of receiving the satellite signal, based on the received light variation.

Abstract: Provided is a radio-controlled watch capable of performing leap second correction even when information on a leap second is not received from a satellite. Provided is a radio-controlled watch that adjusts time by receiving a signal containing time information from a satellite, the radio-controlled watch being configured to: store a leap second correction value to be used for leap second correction with respect to the time information; display a numerical value corresponding to the leap second correction value; receive an instruction operation of changing the leap second correction value from a user in a state in which the numerical value is displayed; and change the leap second correction value in response to the received instruction operation.