Patent ID: 6978685

Claim:
A steering state detecting apparatus comprising: an input shaft connected to a steering member; an output shaft; a torsion bar which has a spring constant K and connects the input shaft to the output shaft; a first sensor portion for outputting an output signal in accordance with rotation of the input shaft which includes a target in a shape of spur gear integrally rotatable with the input shaft including first teeth projected substantially at equal intervals in a peripheral direction of the input shaft, and a magnetic sensor having a magnetoresistive element and arranged to be opposed to the first teeth; and a second sensor portion for outputting an output signal in accordance with rotation of the output shaft which includes a target in a shape of spur gear integrally rotatable with the output shaft including second teeth projected substantially at equal intervals in a peripheral direction of the output shaft, and a magnetic sensor having a magnetoresistive element and arranged to be opposed to the second teeth, wherein a steering state at the steering member is detected based on the output signals of the first and second sensor portions, and wherein following inequality is satisfied: 360(deg)/ Z>T ( Nm )/ K ( Nm /deg) wherein Trepresents an allowable maximum value of a rotational torque applied to the steering member and Z represents a number of the first and second teeth.