Patent ID: 8896297

Claim:
A rotating angle detecting sensor comprising: a columnar permanent magnet; and a plurality of magnetic sensors arranged entirely within a circle axially spaced apart from an end face of the permanent magnet, the permanent magnet being formed with a uniform material, having a columnar shape, and being radially double-pole-magnetized; wherein the permanent magnet is formed by a ferrite magnet or an alnico magnet having a diameter of 4 mm to 20 mm and an axial length of 3 mm to 5 mm, wherein the plurality of magnetic sensors is arranged to detect a radial magnetic flux density at a position spaced 0.5 mm to 3.0 mm apart from a central portion of the permanent magnet, the central portion having a diameter equal to or smaller than 20% of the magnet diameter on the end face of the permanent magnet, and wherein the circle has a diameter equal to or smaller than 20% of the magnet diameter and is configured to be concentric with the permanent magnet.