| 摘要 |
A rotation-angle detecting apparatus for detecting a rotation angle of a rotating disc (1) includes a plurality of detection means (3a, 3b) arranged around a rotating shaft (2) of the rotating disc (1) at positions facing each other, each detection means (3a, 3b) detecting a light beam from a scale on the rotating disc (1) and outputting a pair of periodic signals with a 90-degree phase difference; analog-to-digital converting means (5a, 5b) that converts pairs of periodic signals into pairs of digital signals having digital values at predetermined time intervals; digital signal processing means (7) that processes the pairs of digital signals; binarization means (6a, 6b) that binarizes the pairs of periodic signals; and counting means (8a, 8b) that counts the pairs of binarized periodic signals. The digital signal processing means (7) determines the rotation angle based on the pairs of digital signals and count results. |
