| 摘要 |
PURPOSE:To discriminate the distance, shape, etc., of an object from a spot distribution state by allowing two fiber gratings to cross each other closely at right angles, and irradiating one surface with laser light and the object with a diffracted spot from the other surface. CONSTITUTION:The fiber gratings 2a and 2b formed by arraying numbers of optical fibers without any gap cross each other closely at right angles form a spot array projection part 5, which is irradiated with the laser beam to L to radiate light beams Lb in a secondary spot array to the object. When the object is at a long distance, one-several diffracted spots P reach the object and when the object is at a short distance, numbers of spots P are projected, so the number of spots P is counted by a photodetector 8 to know the distance. Further, the size is grasped from the number of spots P in an array and the shape is grasped from the direction of the array. |
