Patent ID: 7279890

Claim:
A tandem rotation detector comprising: (a) a first rotation angle detection mechanism for detecting a rotation angle of a rotary shaft arranged in a center of a cylindrical housing including: (i) a coil of a first outer core provided on the inner surface of the cylindrical housing to generate a magnetic flux, (ii) a coil of a first inner core fixed on the rotary shaft confronting the first outer core to receive the magnetic flux generated thereby, (iii) a coil of a first rotor core fixed on the rotary shaft, wherein the magnetic flux generated by the first inner core induces a voltage in the first rotor core, and (iv) a coil of a first stator core provided on the inner surface of the cylindrical housing to receive a magnetic flux from the coil of the first rotor core; and (b) a second rotation angle detection mechanism placed side by side with said first rotation angle detection mechanism for detecting a rotation angle of the rotary shaft, including: (i) a coil of a second outer core provided on the inner surface of the cylindrical housing to generate a magnetic flux, (ii) a coil of a second inner core fixed on the rotary shaft confronting the second outer core to receive the magnetic flux generated thereby, (iii) a coil of a second rotor core fixed on the rotary shaft, wherein the magnetic flux generated by the second inner core induces a voltage in the second rotor core, and (iv) a coil of a second stator core provided on the inner surface of the cylindrical housing to receive a magnetic flux from the coil of the second rotor core, wherein the coil of the first stator core and the coil of the second stator core are positioned between the coil of the first outer core and the coil of the second outer core such that leakage magnetic flux generated by the coil of the first outer core is substantially cancelled by leakage magnetic flux generated by the coil of the second outer core.