| 摘要 |
PURPOSE:To take a measurement of distance from long distance to short distance and further to a macrophotographic range without using any mechanical driving part by providing the 1st light emitting element used to measure distance within a specific range and the 2nd light emitting element used to measure shorter distance than the specific range. CONSTITUTION:When an object at long distance (X1), a light beam 3A emitted by the 1st IRLED 2 is reflected by; the object 1 (at position X1) and transmitted through a condenser lens 4 as a reflected light beam 3B1 to form a spot image P1 at one point on a PSD 5. When the object 1 is at short distance (X2), on the other hand, the light beam 3A is reflected by the object 1 (X2) to become a reflected light beam 3B2, which forms a spot image P2 at the lower limit of effective length on the PSD 5. A light beam 8A emitted by the 2nd LRLED 6, on the other hand, is transmitted through the 2nd projection lens 7, reflected by the object 1 in the macrophotographic area shown by distance X3, and transmitted through the condenser lens 4 as a reflected light beam 8B to form a spot image P3 on the PSD 5. |
