| 摘要 |
PURPOSE:To speed up the selection of the presence position of an object and the arithmetic of distance information by automatically switching to projecting means which projects light on the peripheral region of the object unless the level of reflected light from the central part fails to reach a specified value in the 1st integrating operation. CONSTITUTION:Light emitting elements IRs, and IRw1 and IRw2 project light upon the center part Obs and peripheral parts Ob1 and Ob2 on the reflecting surface Ob of the object respectively and light receiving elements SPC1 and SPC2 which are arranged at an interval of specific base line length (l) receive reflected light from them. When the center part Obs on the object reflecting surface Ob is at finite distance, the distance is measured by the element IRs and a camera is put in focus on according to the distance. When the center part Obs is at extremely long distance, on the other hand, the level of its reflected light is low and the rise level of an integrator output is small, so that it is judged that the distance of the center part Obs to the object is infinite. For the purpose, the elements IRw1 and IRw2 for the peripheral parts Ob1 and Ob2 are switched to perform rise integration and fall integration again, and thus the distance of the peripheral parts Ob1 and Ob2 to the object is measured, so that the camera is put in focus based on the distance.
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