Patent ID: 8047066

Claim:
A steering angle sensing apparatus comprising: a case; a cover coupled to the case; an output shaft of a steering torque sensor; wherein at least a portion of the output shaft is disposed between the case and the cover; a shaft gear directly coupled to the output shaft; a first sub gear rotating with the shaft gear; a second sub gear having a gear ratio different from a gear ratio of the first sub gear and rotating with the shaft gear; a first magnet coupled to the first sub gear; a second magnet coupled to the second sub gear; a first and a second angle detecting portion disposed on the cover and spaced a predetermined distance respectively from the first and second magnets, and respectively outputting rotated bit values corresponding to rotated angles of the first and second magnets, wherein the first and second angle detecting portions are rotary hall integrated circuits; and a steering angle calculating portion configured to calculate an absolute steering angle from the rotated bit values, wherein the steering angle calculating portion calculates a difference between the rotated bit values outputted by the first and second angle detecting portions, and multiplies a uniform gain value to the calculated difference between the rotated bit values.