Patent ID: 6335618
Filing Date: 2002-01-01
Classification: G01B,G01D

Abstract:
An inductive absolute position transducer, comprising:a scale member; a read head member, the read member and the scale member movable relative to each other along a measuring axis; at least one transmitter winding formed on the read head member, at least one set of receiver windings formed on the read head member, each set comprising at least two receiver windings, and a signal generating and processing circuit electrically connectable to at least one transmitter winding and at least one set of receiver windings; and a plurality of flux modulating elements formed on the scale member and spatially distributed along the measuring axis, the flux modulating elements arranged into at least one track, wherein: for each track, the flux modulating elements of that track apply a first modulation to the inductive coupling between at least a first transmitter winding corresponding to that track and at least one set of receiver windings corresponding to that track based on the spatial distribution of the flux modulating elements of that track along the measuring axis and on a relative position between the read head member and the scale member along the measuring axis, and for at least one track, the flux modulating elements of that track have at least one varying flux modulating property that varies between the flux modulating elements and along the measuring axis to apply a second modulation to the inductive coupling between the at least first transmitter winding and the at least one set of receiver windings corresponding to that track based on the at least one flux modulating property.