Detection signal processing circuit and rotation detecting device which comprises selbige

Detection signal processing circuit (10) for processing a first analog detection signal (Va) and a second analog detection signal (Vb), which have a phase difference, and which, when a rotating body rotates by a rotation detecting sensor (20) output, which is arranged to the rotating body opposite is, the detection signal processing circuit (10) comprising: a first converter circuit (30a) the first analog detection signal (Va) in a first binary detection signal (Sa) transforms; a second converter circuit (30b), the second analog detection signal (Vb) into a second binary detection signal (Sb) transforms; a rotation direction decision circuit (40) which detects a direction of rotation of the rotating body based on level transitions of the first binary detection signal (Sa) and the second binary detection signal (Sb), and a rotation information signal (Sa1 and Sa2) outputs containing information about speed and direction; a mask circuit (50) which is connected to an output line of the rotation direction decision circuit (40) and configured to be capable of containing the transfer of the information stored in the rotation information signal (Sa1 and Sa2) ...