RADIO-WAVE WRISTWATCH - CITIZEN HOLDINGS CO LTD

Title:

RADIO-WAVE WRISTWATCH

Document Type and Number:

WIPO Patent Application WO/2012/132875

Kind Code:

A1

Abstract:

Provided is a radio-wave wristwatch that receives radio waves including day-related information from a satellite in a global positioning system, wherein the number of revolutions of the day-related information is accurately updated even when there is a decrease in a power supply voltage. A radio-wave wristwatch (1) according to the present invention comprises: reception means (11) for receiving radio waves from a satellite and extracting day-related information; timer-circuit halting means for halting the operation of a timer circuit in response to a power supply voltage; timer-circuit halt detection means for detecting that the timer-circuit halting means has halted the operation of the timer circuit (13); a nonvolatile memory (23) for storing the day-related information and the number of revolutions of the day-related information; and revolution number updating means for, when the timer-circuit halt detection means has detected that the operation of the timer circuit has been halted, updating the number of revolutions of the day-related information in accordance with the result of comparing the day-related information extracted by the reception means (11) and the day-related information stored in the nonvolatile memory (23).

Inventors:

KATO AKIRA (JP)
HAGITA TAKUSHI (JP)

Application Number:

PCT/JP2012/056396

Publication Date:

October 04, 2012

Filing Date:

March 13, 2012

Export Citation:

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Assignee:

CITIZEN HOLDINGS CO LTD (JP)
CITIZEN WATCH CO LTD (JP)
KATO AKIRA (JP)
HAGITA TAKUSHI (JP)

International Classes:

G04R20/10

Foreign References:

JP2007315953A	2007-12-06
JP2000065913A	2000-03-03
JP2000352583A	2000-12-19
JPH0822422A	1996-01-23
JP2009250801A	2009-10-29
JP2009168620A	2009-07-30

Other References: