Time-information obtaining apparatus and radio-controlled timepiece

A time-information obtaining apparatus comprising:

• a receiving unit for receiving a standard-time radio wave to obtain and output a time signal, which includes a time code comprising plural bits;
• an input waveform data pattern generating unit for sampling the time signal output from the receiving unit to generate an input waveform data pattern;
• an internal time counting unit with a built-in clock signal generator, for counting a base time based on a clock signal;
• a calculation-waveform data pattern generating unit for generating plural calculation-waveform data patterns having the same time length as the input waveform data pattern based on the base time counted by the internal time counting unit;
• an error detecting unit for comparing sample values of the input waveform data pattern with sample values of the plural calculation-waveform data patterns to detect discrepancies between the input waveform data pattern and the calculation-waveform data patterns, thereby obtaining a number of errors between the input waveform data pattern and each of the plural calculation-waveform data patterns, wherein the number of errors represents a number of discrepancies;
• a present-time correcting unit for correcting the base time counted by the internal time counting unit based on the calculation-waveform data pattern having a smallest number of errors;
• a calculation-waveform data pattern determining unit for determining respective starting positions of the plural calculation-waveform data patterns such that a number of invalid bits not to be compared among bits of the plural calculation-waveform data patterns will be less than a predetermined number;
• and
• an input waveform data pattern determining unit for determining a starting position of the input waveform data pattern so as to conform to the starting positions determined by the calculation-waveform data pattern determining unit.