| 摘要 |
<p>PURPOSE:To widen a distance measuring range without deteriorating distance measuring accuracy by forming a photodetecting lens by an anamorphic lens, and also, providing a light shielding mask for changing a detecting distance, in front of a position detecting element. CONSTITUTION:The photoelectric switch is formed by a projecting means 3 for projecting a light beam to an object X to be detected, a photodetecting means 6 for photodetecting its reflected wave, and a position detecting element consisting of two pieces of photodiodes 8a, 8b which have been installed on the image forming surface of the photodetecting means 6. In that case, a photodetecting lens 5 of the photodetecting means 6 is formed by an anamorphic lens for extending a condensing spot (S1-S3) in the direction orthogonal to the spot moving direction. Also, in the vicinity of the front of the position detecting element, a light shielding mask 9 is installed so as to be freely movable so that the detecting distance can be changed in accordance with a movement of the condensing spots S1-S3.</p> |
