US 2011/0254541 A1Published application

Electromagnetic encoder

AssigneeMitutoyo Corporation

InventorKouji SASAKI

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Abstract

According to the present invention, an electromagnetic encoder includes a number of scale coils arranged on a scale along a measuring direction; and transmitting coils and receiving coils arranged on a grid to be movable relative to the scale in the measuring direction, in which a relative movement amount between the scale and the grid is detected based on variation in magnetic flux detected by the receiving coils via the scale coils at the time of exciting the transmitting coils, and the receiving coils are provided in the measuring direction to be a plurality of sets, one of the sets of the receiving coils being displaced by a ½ phase of a scale pitch relative to the other set of the receiving coils.

Claims4

Dependent claims

An electromagnetic encoder comprising:

a plurality of scale coils arranged on a scale along a measuring direction;
and
a transmitting coil and a plurality of receiving coils, the transmitting coil and the plurality of receiving coils arranged on a grid and being movable relative to the scale in the measuring direction,
wherein:
a relative movement amount between the scale and the grid is detected based on variation in magnetic flux detected by the plurality of receiving coils via the plurality of scale coils at the time of exciting the transmitting coil;
and
the plurality of receiving coils is arranged in the measuring direction in a plurality of sets, one set of the plurality of sets of receiving coils being displaced by a ½ phase of a scale pitch relative another set of the plurality of sets receiving coils.

4 more elements

Dependencies are inferred from the claim text.