Patent ID: 6806484
Filing Date: 2004-10-19
Classification: G01B,G01V

Abstract:
An edge detector for detecting an edge of an object, said edge detector comprising:a first optical fiber, with a receiving end and a transmitting end, adapted to receive laser light at the receiving end and create a light beam at the transmitting end; a second optical fiber, with a receiving end and a transmitting end, positioned such that the receiving end of the second optical fiber receives the light beam and transmits light to the transmitting end of the second optical fiber; and a single optical power detector optically coupled to the transmitting end of the second optical fiber, the optical power detector having an output P indicative of the optical power of the light transmitted through the second optical fiber, the output P having a maximum value Pmax when no object is within the light beam and a minimum value Pmin when the object is fully within the light beam; and a retainer for holding the transmitting end of the first optical fiber and the receiving end of the second optical fiber such that the receiving end of the second optical fiber receives the light beam from the transmitting end of the first optical fiber; wherein the edge of the object is detected when the object partially obstructs the light beam, such that the output P of the single optical power detector is less than the maximum value Pmax and greater than the minimum value Pmin, and wherein at least one of the first and second optical fibers comprises a single-mode fiber.