Patent ID: 8264915
Filing Date: 2012-09-11
Classification: G04R

Abstract:
1. A time information-acquiring apparatus comprising: a receiver configured to receive a standard time radio wave including a time code; an input waveform generator configured to sample a signal output from the receiver and including the time code with a predetermined sampling period and to generate input waveform data with one or more unit time lengths, the input waveform data at each sampling point having one of a first value indicating a low level and a second value indicating a high level; a predicted waveform generator configured to generate plural predicted waveform data, each of the plural predicted waveform data having the one or more unit time lengths, each of the plural predicted waveform data at each sampling point having one of the first value and the second value, and a phase of each of the plural predicted waveform data being shifted by a predetermined number of samples; a correlation calculator configured to arithmetically operate the input waveform data at a sampling point and the plural predicted waveform data at a corresponding sampling point and to calculate correlation values between the input waveform data and the plural predicted waveform data, wherein the correlation calculator is configured to calculate a first correlation value indicating a positive correlation by arithmetically operating the first value of the input waveform data and the first value of the predicted waveform data or arithmetically operate the second value of the input waveform data and the second value of the predicted waveform data, and to calculate a second correlation value indicating a negative correlation by arithmetically operating the first value of the input waveform data and the second value of the predicted waveform data or arithmetically operate the second value of the input waveform data and the first value of the predicted waveform data; a comparator configured to compare the correlation values calculated by the correlation calculator and to detect an optimal value of the correlation values; and a controller configured to detect a head position of a second in the time code based on predicted waveform data related to the optimal value.