| 摘要 |
1,204,738. Shaft encoders. COMPAGNIE FRANCAISE THOMSON HOUSTONHOTCHKISS BRANDT. 24 May, 1968 [6 June, 1967], No. 25033/68. Heading G4H. A shaft encoder includes a plurality of discs 31, 32, 33 with coded perforations sensed by photo-electric cells 51, 52, 53 illuminated by light conductors 41, 42, 43 receiving light from a single source 7. In the embodiment described to prevent errors the disc 31 may either be coded in reflected binary code or it may be sensed by two sets of cells (531, 532, Fig. 2, not shown). Alternatively two discs (311, 312, Fig. 3, not shown), both coded in reflected binary code, may be used. The light conductors are preferably optical fibres. |
