Abstract: An angle detector including an annular stator board (1); a plurality of stators (5) provided on the annular stator board (1) independently of one another and forming slots (10) at constant or various intervals; a magnetic core (11) formed on surfaces of the stators (5); stator windings (4) formed around the magnetic cores (11) and composed of excitation windings (4a) and output windings (4b); a magnetic flux return path plateau (12) provided on each of the surfaces of the stators (5) and provided inward or outward of the stator windings (4); an annular rotor board (6) provided on the magnetic flux return path plateaus (12); and a gap forming board (13) provided on an inner surface (6a) of the annular rotor board (6) and having a board inner surface (13a) whose protrusion state changes according to a waveform. The annular rotor board rotates to cause changes in a gap (14) between each of the magnetic cores (11) and the board inner surface (13a) of the gap forming board (13).

Abstract: It is an object of the present invention to obtain an ultrathin angle detector by disposing an annular rotor board face to face with stator windings of a plurality of stators provided on an annular stator board. An angle detector according to the present invention is constructed by providing magnetic cores and the stator windings on the respective stators provided on a surface of the annular stator board via slots, and disposing a corrugated curved surface formed on a board inner surface of the annular rotor board face to face with the stators so as to obtain an angular signal that changes according to a sinusoidal waveform.