Patent ID: 8497643
Filing Date: 2013-07-30
Classification: H02K

Abstract:
1. A linear scale for obtaining a distance from a reference point, comprising: a scale element having a plurality of magnetic bodies; a scale detection mechanism arranged over a stroke range greater than a scale length of the scale element, the mechanism is adapted to output waveform signals corresponding to a magnetic flux density generated by the magnetic bodies of the scale element; and a plurality of sensors, the sensors constitute the scale detection mechanism, are arranged in a movement direction of the scale element at even intervals corresponding to the scale length, and the sensors are adapted to output waveform signals of the same phase in response to a movement of the scale element to continuously detect the scale element, wherein the scale element has opposite ends each has the same polarity, and the scale element is configured such that an output voltage of the single sensor detecting the end of the scale element is reduced to one-half of an output voltage of the single sensor detecting the remaining portion of the scale element.