Patent ID: 7579829
Filing Date: 2009-08-25
Classification: G01D

Abstract:
1. A multi-turn encoder module, comprising: a rotatable shaft having gears disposed about a periphery thereof; a baseplate having an aperture disposed therethrough and configured to accept at least a portion of the shaft therein, the baseplate further comprising a plurality of geared circular disks, at least some of the geared circular disks comprising an electrically conductive portion; a substrate having a plurality of inductive coils, each of the inductive coils being operably aligned and configured in respect of at least one corresponding opposing geared circular disk and the electrically conductive portion thereof, and a position logic device configured to determine a rotational parameter of the shaft on the basis of the relative positions of the geared circular disks respecting one another as they are sensed by the inductive coils; wherein the substrate opposes the baseplate, the shaft is operably and mechanically connected to at least one of the geared circular disks by the shaft gears, rotation of the shaft causes the at least one geared circular disks to rotate and thereby cause the remaining geared circular disks to rotate according to a predetermined gear reduction ratio, and each of the inductive coils is configured to generate an output signal representative of a revolution of the geared circular disk operably aligned in respect thereof and opposed thereto, thereby to permit a number of revolutions the shaft has rotated to be determined by the position logic device.