Torsion angle detection apparatus and torque sensor

A torsion angle detection apparatus, wherein a pair of optical type of encoders are disposed on the coaxial center at a proper interval in the axial direction, and also, the measured shaft is inserted into the axial center position thereof and is secured to the rotary portion of each of the encoders, so that the torsion angle of the measured shaft may be detected with high accuracy and high speed response property from the difference in the detection position by each encoder by the use of an optical type of encoder of high resolution.high speed response property.