| 摘要 |
PURPOSE:To enable detection of a specific point and very small displacement with high accuracy and reliability by including a light source and a reflection part as well as at least two photodetectors, and detecting a movement with the outputs from the two photodetectors when one among the three photodetectors move. CONSTITUTION:A light source 1 may be any of an incandescent lamp, LED, etc. and is made incident as parallel luminous fluxes into a reflection part 3 by a collimator lens 2. The part 3 consists of a condenser lens 4 and a reflecting mirror 5, which move integrally in the direction Z shown by an arrow 6. The optical axis of the light emitted from the part 3 moves in parallel with the displacement of the lens 4 and the mirror 5 in the direction Z. A photodetecting part 7 is made of photodiodes which are approximately perpendicular to the plane of the figure and are arrayed in the direction Z. The reflection part is so constituted that the forward and backward optical axes deviate slightly from each other. As a result, the optical sensor which is highly durable and reliable and can detect the specific position and very small displacement is realized. |
