Abstract: An optical switch has at least first, second, and third optical fibers disposed generally parallel to each other and spaced at non-equal intervals in a direction substantially perpendicular to an optical axis of each of the optical fibers. The optical fibers have tip portions disposed approximately along a straight line extending in a direction substantially perpendicular to the optical axis of each of the optical fibers. A first non-movable guiding structure guides a beam of light emitted from the first optical fiber to the second optical fiber along a first optical path disposed between the tip portion of the first optical fiber and the tip portion of the second optical fiber.

Abstract: The invention equalizes the lengths of optical paths required in optical communication among optical paths constructed by plural optical fibers. Optical fibers parallel to each other at non-equal intervals are set to ADD, OUT, IN and DROP, and are used for add-drop. An ADD-OUT optical path of an optical path length A+2E from the optical fiber to the optical fiber through a fixing mirror and a movable mirror, and an IN-DROP optical path of an optical path length C+2E from the optical fiber to the optical fiber through a movable mirror and a fixing mirror are formed. When the movable mirrors are escaped, an ADD-DROP optical path of an optical path length A+B+C+2E from the optical fiber to the optical fiber through the fixing mirrors, and an IN-OUT optical path of an optical path length B+2D+2E from the optical fiber to the optical fiber through fixing mirrors are formed. Three optical paths except for ADD-DROP are set to the same length by setting A=C=B+2D.

Abstract: An optical fiber with lens for constituting an optical functional component capable of light beam propagation, which improves the stability in holding and handling and contributes to downsizing. To one end of a single mode (SM) optical fiber, which is a main part of the optical fiber with lens, a graded index (GI) optical fiber functioning as a convergence type rod lens and having a predetermined length is integrally connected, and this GI optical fiber is thinner than SM optical fiber. The refractive index distribution constant {square root}A of the GI optical fiber is from 1.0 to 4.0, and the end surface thereof is inclined at from 2.0 degrees to 4.0 degrees. Further, the GI optical fiber may be constituted only by a core part without a clad part.

Abstract: An image input unit inputs a plurality of images in a time series. Each input image includes a boundary line extending toward a vanishing point on a plane. A reverse projection image generation unit generates a reverse projection image of each input image by projecting information related to each input image onto the plane. A boundary line detection unit detects the boundary line from the reverse projection image by identifying a boundary line candidate on each reverse projection image.

Abstract: Circuit ends of a cancel loop circuit and a frequency generator circuit are connected with circuit lands in such a manner that the two circuits are not allowed to electrically communicate with each other. The cancel loop circuit and the frequency generator circuit are subjected to an electrical conductivity test to detect any short circuit therebetween. After successful testing, the lands located adjacent each other at one side of the circuits are connected with each other, thereby electrically communicating the cancel loop circuit and the frequency generator circuit to obtain a completed coil circuit.