TORQUE DETECTOR

PURPOSE:To provide a torque detector which achieves higher towque detection accuracy even when a rotational speed of a rotating shaft member changes. CONSTITUTION:Magnetic heads 14a and 14b are arranged axially at a specified interval L while a magnetic head 14c is arranged circumferentially at a specified angle theta0 with respect to the magnetic head 14a. A position signal is recorded on magnetic recording layers 12a and 12b through the magnetic heads 14a, 14b and 14c and a phase difference DELTAt between reproduction position signals to be reproduced through the magnetic heads 14a and 14b is detected. Time interval (t) of continuing two reproduction position signals to be reproduced from the magnetic heads 14a and 14c is detected. Twisting angle theta and moreover, a torque T of the rotating shaft member 10 are calculated from the time interval (t) and the phase difference DELTAt thus obtained. Since the detection of the torque uses the phase difference DELTAt and the time interval (t) (not rotational speed), the torque T can be detected directly with the specified angle theta0 as reference without receiving effect of the rotational speed of the rotating shaft member 10 and of changes therein when the signals are recorded.