| 摘要 |
PURPOSE:To make a shape small-sized, and also to obtain a detecting signal of a high level and a high S/N ratio by detecting optically a rotation. CONSTITUTION:A light 5a from a plane light source 5 passes through all slits 7a of a rotating plate 7, is irradiated to a plane-like photoelectric converting means 8, and also shielded by the rotating plate 7. When the rotating plate 7 rotates, the light is irradiated alternately to a photoelectric converting element small piece 9a and 10a, a photovoltaic current of an opposite phase to each other is generated in each small piece 9a, 10a, supplied to photovoltaic current -voltage converting circuits 13, 14 respectively, and voltages Va, Vb being proportional to the irradiating light quantity, respectively are obtained. Also, as for the voltage Va and Vb, their difference is derived in a differential amplifying circuit 15, and its output voltage vO is used as a rotating information detecting signal such as a speed detecting signal or a phase detecting signal, etc. |
