Patent ID: 8455748

Claim:
A pitch detection device, the device comprising: an input means for inputting a signal; a clock generation means for generating a clock signal; a pitch calculation means for calculating a pitch of the signal by determining a duration of one cycle of the signal that regards one clock of the clock signal as the smallest base unit; a cycle detection means for detecting one cycle of a waveform of the signal; a cycle measurement means for discretely measuring a measurement time of one cycle of the signal during one clock of the clock signal, for each one cycle of the signal detected by the cycle detection means; a cumulative cycle measurement means for cumulatively adding, for every one cycle of the signal, the measurement time corresponding to each one cycle of the signal measured by the cycle measurement means to obtain a cumulative time, the cumulative adding ending when the cumulative time equals or exceeds a smallest measurement time that realizes a required pitch error accuracy; and a frequency counting means for counting frequencies of the signal included within the cumulative time when the cumulative adding ends; wherein the pitch calculation means calculates the pitch of the signal from the cumulative time and a number of the counted frequencies.