Patent ID: 7945821

Claim:
A time lag measuring device for measuring an unknown time lag between generations of two pulse signals, comprising: a reference signal generating section generating a reference signal having a known cycle; an amplitude detecting section obtaining two amplitudes of the reference signal at a timing at which each of the pulse signals are generated, so as to substantially achieve a same effect as in a case where the amplitudes of the reference signal are sampled at two timings associated with respective generation timings for the two pulse signals, the two timings being spaced with an interval corresponding to a phase difference of approximately π/2 [rad] of the reference signal; a phase difference detecting section obtaining a phase of the reference signal at a generation timing for each of the pulse signals and a phase difference thereof between the generation timings according to the two amplitudes obtained at the generation timing for each of the pulse signals; a correcting section correcting the phase difference detected by the phase difference detecting section relative to one of an error in the reference signal and an error in the phase difference of approximately π/2 [rad]; and a time lag calculating section obtaining a time lag between the generations of two measurement pulse signals according to the phase difference corrected by the correcting section.