US Patent 9366523 Rotation angle sensor

The rotational angle sensor for measuring the rotational angle of a shaft has two code disks, the first code disk of which is rotationally fixed to the shaft while the second code disk is held between the shaft and the housing by two spring groups. Each code disk is assigned to a sensor. The sensor of the first code disk generates a periodic rotational angle signal while the sensor which is assigned to the second code disk generates a coarse signal (U2) which is different from the first signal and which can be used to ascertain which rotation of n possible rotations the shaft is in, wherein n>1.