| 摘要 |
PURPOSE:To surely detect the existence of an object in the nearest range by a method wherein when reflection beams are incident to a photoelectric element or an added photoelectric element thereof in the nearest range side corresponding to a focusing unfeasible distance zone, an alarm is issued therefor. CONSTITUTION:A projecting light receiving face part 20b is extended to the nearest distance side of a photoelectric element 9 opposed to the nearest distance zone. When an object of range finding exists within the nearest distance zone in this state, reflection beams from the object pass through an image forming lens 4 and form an image on the projecting light receiving face part 20b as shown by S. With this, a detection that a range finding object exists within the nearest distance zone is performed by means of a photoelectric conversion circuit 15, a voltage comparison circuit 19, a registor 24 and a logic circuit 28, thus, a focusing unfeasible alarm is given. In this way, the existence of a range finding object within the nearest distance is surely detected. |
