| 摘要 |
PURPOSE:To obtain a focusing state which is invariably accurate within the entire temperature range of practical use and free from an error by correcting measured distance information so that the state of focusing decision making does not change irrelevantly to temperature variation. CONSTITUTION:A two-division photodetection part equipped with, for example, two photodetectors 1 and 2 is used as a 1st detecting means which measures the distance to an object. Then the output of one photodetector 1 is corrected with variation in the resistance of, for example, a heat sensing resistance 4 as a 2nd detecting means with temperature and the measured distance information obtained by the two photodetectors 1 and 2 is corrected into information at set reference temperature. In another way, temperature information detected by the 2nd detecting means 4 is contrasted with the quantity of measured distance deviation corresponding to case-studied temperature variation to correct the measured distance information into information at the set reference temperature. Consequently, the invariably correct focusing state is obtained irrelevantly to the expansion and contraction of distance measurement part constituent components due to temperature variation. |
