Satellite radio-controlled wristwatch
View Patent ↗A reception time period required for time adjustment is reduced in a satellite radio-controlled wristwatch. A satellite radio-controlled wristwatch according to the present invention includes: a satellite radio wave reception unit including an antenna for receiving a satellite radio wave, a high frequency circuit, and a decoder circuit; a clock circuit for holding and counting an internal time; and a controller for controlling a timing of at least a time information acquisition operation of acquiring time information from the satellite radio wave received by the satellite radio wave reception unit, the controller being configured to selectively execute, in the time information acquisition operation, based on error evaluation of the internal time: a shortened time adjustment operation of ending the time information acquisition operation at a stage at which head information representing a head of unit information is received, and adjusting the internal time based on a timing at which the head information is received; and a normal time adjustment operation of receiving the time information, and adjusting the internal time based on the time information.
1. A satellite radio-controlled wristwatch, comprising:
a satellite radio wave reception unit comprising an antenna for receiving a satellite radio wave, a high frequency circuit, and a decoder circuit;
a clock circuit for holding and counting an internal time; and
a controller which controls a time information acquisition operation of acquiring time information from the satellite radio wave received by the satellite radio wave reception unit,
the controller being configured to selectively execute, in the time information acquisition operation, based on error evaluation of the internal time:
a shortened time adjustment operation of ending the time information acquisition operation at a stage at which head information that is preamble data of a fixed value representing a head of unit information is received, and adjusting the internal time based on a timing at which the head information is received; and
a normal time adjustment operation of receiving the time information, and adjusting the internal time based on the time information.
2. The satellite radio-controlled wristwatch according to claim 1 , wherein, in the shortened time adjustment operation, the controller executes the normal time adjustment operation when an adjustment amount of the internal time is equal to or more than a predetermined value.
3. The satellite radio-controlled wristwatch according to claim 1 , wherein in the normal time adjustment operation the controller receives the time information a first time and a second time when an adjustment amount of the internal time is equal to or more than a predetermined value or when an index representing a reception intensity of the received satellite radio wave is equal to or less than a predetermined value, and adjusts the internal time when the time information received the second time matches with the first time information received.
4. The satellite radio-controlled wristwatch according to claim 1 ,
wherein the clock circuit holds information relating to a date to be updated when the internal time counted by the clock circuit arrives to a time point at which the date information is required to be updated, and
wherein, in the shortened time adjustment operation, the controller updates the information relating to the date at a time point at which the internal time is adjusted when a time point at which the head information is received is within a predetermined range from a time point at which the information relating to the date is updated in the internal time, and when the information relating to the date has not been updated at a time point at which the internal time is adjusted.
5. The satellite radio-controlled wristwatch according to claim 1 ,
wherein the clock circuit holds information relating to a date to be updated when the internal time counted by the clock circuit arrives to a time point at which the date information is required to be updated, and
wherein in the shortened time adjustment operation, the controller inhibits the shortened time adjustment operation when a time point at which the head information is received is within a predetermined range from a time point at which the information relating to the date is updated in the internal time.