| 摘要 |
PURPOSE:To reduce a space occupied by a sensor, by a method wherein a detecting means, outputting a speed signal in accordance with the passing speed of respective slits of a slit plate only during a period when the alit plate, provided on a carrier, is detected, is provided in the title detector. CONSTITUTION:When light beams, generated by a light emission diode D1, are intercepted by the upper area UA of a slit plate 16, the potential of the collector of a phototransistor Tr1 becomes a H-level and a carrier detecting signal is outputted from a terminal T1. When the light beams, generated by the light emission diode D2, are intercepted intermittently by the lower area LA of the slit plate 16, in which slits 16a are formed, the potential of the collector of the phototransistor Tr2 becomes H-level intermittently and a speed signal, having a pulse frequency corresponding to the moving speed of the slit plate 16, is outputted from the terminal T2. |
