Patent ID: 6828783
Filing Date: 2004-12-07
Classification: G01D

Abstract:
An angle measuring instrument, comprising:a first device configured to determine an absolute angular position of a rotating shaft within one shaft rotation; and a second device configured to determine a number of executed shaft rotations having: a gear including at least one gear unit configured to convert rotary motion of the shaft into a rotary motion having a defined reduced ratio, the gear unit including at least one gear wheel configured to rotate in a defined ratio to the rotary motion of the shaft; and a detecting device configured to generate sensor signals positionally dependent and dependent upon the number of executed shaft rotations, the detecting device configured to scan reduced rotational movements of the shaft, said detecting device including; a graduation structure having alternating electrically conductive and electrically non-conductive graduation regions; and a scanning device movable relatively to the graduation structure, said scanning device including: an excitation device configured to generate an electromagnetic excitation field; and a sensor device configured to scan the graduation structure and to transmit the sensor signals dependent upon the number of executed shaft rotations.