| 摘要 |
<p>An optical encoder includes a light source (1), a scale (2) which is irradiated by the light source and has a fine pitch pattern and a coarse pitch pattern in one track, a photo detector array (9) which detects transmitting light or reflected light from the scale which are emitted from the light source, a signal processing means (101) including first initial-stage amplifier means that generates a position detection signal from the photo detector array, and a control means that uses an output signal from the first initial-stage amplifier means to control a light amount variation of the light source. The optical encoder can operate in a high resolution detection mode that forms the photo detector array at a first pitch to detect the fine pitch pattern and a low resolution detection mode that forms the photo detector array at a second pitch to detect the coarse pitch pattern.</p> |
