Electronic watch


PURPOSE:To automatically correct time at arbitrary time on an electronic watch by calculating the difference between the absolute value of the difference between a standard time signal and a counted time and a specified number when the absolute value is higher than a predetermined value. CONSTITUTION:The differences between the standard time signal externally received through registers 1, 2 and counted time signal in an electronic watch is calculated by an arithmetic unit 11, and applied to a register unit 7 consisting of 10-digit flip-flops FF71-73 and 1-digit flip-flops FF74-77. When the difference becomes in absolute value B2 30, a NAND gate 15 produces an output ''0'', while when the absolute value B2 becomes higher than 30, the NAND gate 15 produces an output ''1''. When the output of the NAND gate 15 becomes through a controller 12 ''0'', switching units 4, 9 and 3, 8 are respectively opened and closed to allow the unit 11 to calculate 60-B2. When the result of the unit 11 becomes lower than 30, a correcting unit becomes in operating state to automatically correct the time by quick feed or stop or the like of the time in response to the positive or negative information from the unit 11 and the content of the register unit 7. Therefore, it can automatically correct the time difference within + or -30sec. at arbitrary time except at the on the hour time signal.




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Cited By (3)

    Publication numberPublication dateAssigneeTitle
    EP-1628175-A1February 22, 2006Fujitsu LimitedTime management device and time management method
    EP-1628175-A4July 30, 2008Fujitsu LtdZeitverwaltungseinrichtung und zeitverwaltungsverfahren
    US-7555651-B2June 30, 2009Fujitsu LimitedTime management apparatus and time management method