Patent ID: 7288974
Filing Date: 2007-10-30
Classification: G04R

Abstract:
1. A wave correction clock that counts time, receives a wave signal, having time information defined by a pulse width of a rectangular pulse having a predetermined basic period by a receiving section and detects time information from the pulse width of each rectangular pulse to correct the counted time thereof based on the detected time information, comprising: an internal reference period generating section that generates a reference pulse at an internal reference period that is same as the basic period of the rectangular pulse; a period measuring section that measures a signal period of the rectangular pulse received by said receiving section; a time difference measuring section that obtains a phase difference of the reference pulse with respect to the rectangular pulse; and a correcting section that corrects, when a rectangular pulse which satisfies a predetermined condition is detected, generation timing of the reference pulse such that the generation timing is synchronous with the rectangular pulse, based on the phase difference obtained by the time difference measuring section, wherein the correcting section obtains, when a plurality of adjacent rectangular pulses whose measured signal periods are within a predetermined range are detected, correction time based on an average value of the phase differences obtained by the time difference measuring section, and corrects generation timing of the reference pulse based on the correction time.