摘要 |
A linear encoder system includes an encoder magnet having alternating magnetic zones. The end ones of the magnetic zones are tapered. A distance between the centers of the tapered magnetic zones defines a span. First and second encoder sensors, sensitive to the alternating magnetic zones, are spaced apart a distance equal to the span. As the encoder magnet moves into alignment with one tapered magnetic zone, and out of alignment with the other magnetic zone, the decrease in signal from one magnetic zone is approximately equal to the increase in signal from the other magnetic zone. In one embodiment of the invention, a third encoder sensor is positioned midway between the first and second encoder sensors. <IMAGE> |