| 摘要 |
Apparatus for detecting proximity between a first object (target object) and a second object (reference object), comprising a light source (1) and a light detector (3) adapted to receive resulting back-scattered light from the reference object when illuminated from the light source (1), whereby the intensity of hackscattered light to the light detector (3) is utilized as a measure of said proximity. The target object (2) comprises an optical device (4) having a focal plane (7) and being adapted to be illuminated by the light source (1). The axes of the light rays from the light source (1) and the back-scattering to the light detector (3) have mutually closely adjacent and substantially parallel or coincident portions. Said proximity corresponds to a distance (relative position) between the target object (2) and the reference object (6, 8) wherein the reference object is located substantially at the focal plane. |
