Patent ID: 6957590

Claim:
A rotational angle detecting apparatus comprising: a plurality of detecting means, disposed respectively to face a target made of a magnetic material and provided on a rotating member, for detecting the target and outputting detection signals having phases according to the position of the target which changes with a rotation of the rotating member; operating means for operating a predetermined operation on the detection signals respectively outputted from the detecting means; converting means for converting a result of the operation operated by the operating means into the electrical angle of the detection signals based on ones of a plurality of tables and a plurality of conversion formulas, said tables representing the correlation of each operation result obtained by operating the predetermined operation by the operating means in advance for different gaps between the target and the detecting means with a corresponding electrical angle of the detection signals, and said conversion formulas representing the relationship between the operation result and the electrical angle of the detection signals for different gaps between the target and the detecting means; and determining means for determining the gap based on the detection signals respectively outputted from the detecting means, wherein the converting means converts the result of the operation operated by the operating means into the electrical angle of the detection signals based on one of the table and the conversion formula corresponding to the gap determined by the determining means, and detects a rotational angle of the rotating member based on the obtained electrical angle.