| 摘要 |
PURPOSE:To switch a focusing circuit in accordance with a photometric value in order to reduce erroneous focusing caused by the change of normal light by the movement of an object while Performing the focusing of a moving body. CONSTITUTION:When a PSD 18 receives reflected light from the object 16 being the luminous flux projected from an IRED 14, it outputs two photoelectric conversion signals depending on an incident position and an incident light quantity. A ratio calculation circuit 34 and a sum calculation circuit 35 calculate the added value and the ratio of the two photoelectric conversion signals. A switching circuit 37 compares the brightness of the object detected by a photometry circuit 36 with specified brightness. Then, a CPU 41 obtains a value related to the moving speed of the object 16 based on the output from the circuit 35 in the case that the detected brightness of the object is higher than the specified brightness and based on the output from the circuit 34 in the case that the brightness of the object is lower than the specified brightness, respectively. |
