| 摘要 |
<p>The encoder includes a scale (10) provided with a periodic pattern (11), a sensor (20) relatively movable with respect to the scale and reading the periodic pattern to output analog signals each having a changing period corresponding to the periodic pattern and having mutually different phases, an A/D converter (30) performing time-division analog-to-digital conversion on the analog signals output from the sensor to produce digital signals, and a phase detector (60) detecting a phase from the digital signals. The encoder further includes a corrector (70) calculating a correction value by using a relative movement speed of the scale and the sensor and the detected phase detected by the phase detector, and calculating a corrected phase from the correction value and the detected phase, and a position detector (80) calculating a position in a direction in which the scale and the sensor are relativity moved by using the corrected phase.</p> |
