| 摘要 |
PURPOSE:To facilitate the processing of outputs, by satisfying prescribed conditions in the range detecting device for camera which focuses the reflected light from an object due to the light, which is projected from a light emitting element, on a one-dimensional photodetector. CONSTITUTION:The light from a light emitting element LED becomes parallel beams through a lens L1 and is projected to an object to be photographed, and the reflected light is focused on a one-dimensional photodector (PSD) through a lens L2. When the base length between lenses L1 and L2, the length between electrodes A and B of the PSD, the closest focusing distance of the camera, and the length between surfaces of lenses L1 and L2 and the PSD are denoted as (d), (e), lm, and (f) respectively, elm/11d>=f is satisfied to obtain relation l= (df/e)i1/i. That is, a lengh (l) to the object to be photographed proportional to the ratio i1/i2 of currents i1 and i2 outputted electrodes A and B. An output V4 of a processing circuit constisting of operational amplifiers A1-A3 is proportional to (l), and thus the processing of outputs i1 and i2 of the PSD is facilitated. |
