| 摘要 |
<p>A linear encoder comprises a light source, a main scale provided with a measuring pattern having a constant pitch, an index scale to which a measuring pattern having a constant pitch is mounted, and a light receiving element. The light receiving element detects the brightness generated by these patterns superposed one upon another by relative movement of the main scale with respect to the index scale. The linear encoder further comprises pattern end detecting means for detecting the end portion of the measuring pattern provided on the main scale so that the position of the end portion is used as an origin of the encoder.</p> |
