| 摘要 |
PURPOSE:To detect the rotation angular velocity of a sprocket shaft with high precision, by attaching a gear, having teeth at equal intervals on the outside circumferential part to the shaft and using tooth parts of this gear as light shielding parts and using inter-tooth parts as light-transmissive parts. CONSTITUTION:Teeth are provided at equal intervals on the outside circumferential part of a sprocket gear 1. Tooth parts of this gear are used as light shielding parts, and inter-tooth parts are used as light-transmissive parts. Photodetecting elements whose number is larger than the number of teeth by one are provided at equal intervals between optional teeth of said sprocket gear 1. The light from a light source 10 is transmitted through the sproket 1 and reaches a photodetector 11 through a pinhole of a light shielding plate 14, thereby detecting the angular velocity with high precision. |
