摘要 |
An optical transducer includes a photo-electric converter (OPS) supported by a shank flange rail and optical modulators (1) respectively attached to hammers (50) of an automatic player piano; since a neck portion (1c) makes a photo-modulating pattern (1e) closer to the rotational axis (53b) of each hammer (50) than a boss portion (1b) adhered to the side surface of the hammer shank (57a), the photo-modulating pattern (1e) is rotated in a narrow space in the vicinity of the rotational axis (53b) so as to permit the photo-electric converter (OPS) to monitor the hammer motion between the rest position and the end position without any interference with other component parts, and the boss portion (1b) is easily adhered to the side surface under the condition that a worker lifts the hammer (50) over the adjacent hammers. |