| 摘要 |
In an electromagnetic induction type absolute position measuring encoder having two or more tracks which includes: two or more rows of scale coils 14-1, 14-2, each row including scale coils numerously arranged on a scale 10 along a measuring direction so as to have a scale pitch »1, »2 different from that of another row; and transmitter coils 24-1, 24-2 and receiver coils 20-1, 20-2 provided on a movable grid 12 relative to the scale 10 in the measuring direction so as to face the scale coils 14-1, 14-2, and which can measure an absolute position of the grid 12 with respect to the scale 10 on the basis of a flux change detected at the receiver coil 20-1, 20-2 via the scale coil 14-1, 14-2 when the transmitter coil 24-1, 24-2 is excited, coil lines 14-1b, 14-1c, 14-2b, 14-2c are added to at least one side of the scale coils 14-1a, 14-2a in the measuring direction at least in one of the tracks. Thus, an induced current at the scale coil 14-1, 14-2 when the transmitter coil 24-1, 24-2 is excited is increased, thereby improving a detection signal intensity at the receiver coil 20-1, 20-2. |
