Radio-controlled timepiece and control method for a radio-controlled timepiece

Abstract

A radio-controlled timepiece that receives a standard time signal containing a time code and adjusts the time based on the received standard time signal includes: a reception means that receives the standard time signal; an analog / digital conversion means that digitizes the received standard time signal based on a prescribed threshold value; a time counter that keeps time; a time code generating means that generates a reference time code based on the time counted by the time counter; a duty evaluation means that calculates the pulse duty cycle of the digital signal output from the A / D conversion means, and determines if the received pulse duty cycle that is calculated matches the duty cycle of the reference time code generated by the time code generating means; a level changing means that changes the relative level of the threshold value to the reception signal if the duty evaluation means determines that the received pulse duty cycle does not match the duty cycle of the reference time code; and a time code decoding means that decodes the digital signal and demodulates the time code if the duty evaluation means determines that the received pulse duty cycle matches the duty cycle of the reference time code.

Description

technical field [0001] The present invention relates to a radio wave corrected timepiece and its control method which receives a standard radio wave with time information and corrects the time according to the received standard radio wave. Background technique [0002] Conventionally, radio-controlled timepieces capable of receiving standard radio waves are known (for example, refer to Patent Documents 1 and 2). [0003] The standard radio wave is amplitude modulated, and the radio-controlled timepiece has a binarization circuit in the receiving circuit. The binarization circuit uses a filter or the like to extract the envelope of the received signal, and then compares the envelope signal with a comparator or the like. and reference voltage and perform binarization. Then, the radio-controlled timepiece acquires time information based on the time code signal obtained by the binarization circuit, and displays the time. [0004] Furthermore, these radio-controlled timepieces ...

AI Technical Summary

Problems solved by technology

[0009] However, in this method, it takes at least several minutes until it can be judged whether the correct time information is obtained

Therefore, for example, it takes time until it is judged that the receiving environment has deteriorated and correct time information cannot be obtained, and accordingly there is a problem of increased power consumption.

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