Patent ID: 7844386

Claim:
A reference signal generator in which an angle sensor fixedly disposed on a rotating object sequentially detects a plurality of teeth that are mounted at fixed angular intervals on said rotating object, the plurality of teeth comprising a first tooth, a second tooth, and a third tooth, said first tooth and second tooth being adjacent, said first tooth and said third tooth being adjacent, whereby a time interval between adjacent teeth is measured and a measurement and control reference signal that corresponds to an arbitrary rotational angle is generated, said reference signal generator comprising: rotational trend calculating means for calculating increasing, decreasing and other rotational trend in the rotational speed of said rotating object at a time when said first tooth is detected by said angle sensor in an n−k th cycle of rotation of said rotating object (n, k: natural numbers, and n>k), said calculated rotational trend based on a first time interval between the second tooth and the first tooth, the second tooth detected immediately prior to the first tooth in the (n−k) th cycle, and a second time interval between said first tooth and the third tooth, the third tooth detected immediately after said first tooth in said n−k th cycle; rotation time predicting means for predicting the time interval between said first tooth and said third tooth in the n th cycle, wherein the predicted time interval is based upon a time interval between said second tooth and said first tooth in the n th cycle, a difference among the first time interval and second time interval, and the calculated rotational trend; and reference signal generating means for generating a reference signal during a time interval between a time at which said angle sensor detects said first tooth in the n th cycle and an approximate time at which said angle sensor detects said third tooth, the reference signal having a plurality of pulses wherein number and time spacing of the plurality of pulses is determined at least in part by subdividing said predicted time interval according to a prescribed angular resolution.