| 摘要 |
PURPOSE:To obtain range finding information matching with a main subject by providing a center weighting means for weighting range finding information on the periphery of the center part of a photographic image plane more than on other parts. CONSTITUTION:A projection lens 2 is formed of three lenses with different optical axes in one body and signal light emitted by an infrared-light emitting element 1 is split and projected on three different places, i.e. the center and peripheral parts of the photographic image plane and all reflected light beams are incident on a photodetecting element 4. The photodetecting element 4 uses a semiconductor position detector and detects the incidence position of reflected light which changes with subject distance to find the range. Then, this semiconductor position detector varies in the rate of outputs of both terminals according to the photodetection position of the incident light and the ratio of the outputs is detected to calculate the subject range. For the purpose, a circuit A is connected as a concrete processing circuit to the photodetecting element 4. Therefore, the range finding information on the subject is obtained without prefocusing operation, etc. |
