| 主权项 |
1. A device for splicing two optical fiber ends to each other comprising:
fixtures, each fixture holding one of the two optical fiber ends so that longitudinal directions of the two optical fiber ends are substantially parallel to each other, motors connected to the fixtures for moving the fixtures and thereby the two optical fiber ends, electrodes for producing an electric arc between points of the electrodes, the electric arc heating regions of the two optical fiber ends at end surfaces to fuse material at the end surfaces together to give a splice, an imaging system for capturing pictures of at least the end surfaces in a viewing direction, an optical system, an electronic circuit unit comprising:
a control unit connected to the motors for driving them, to the electrodes for energizing the electrodes and to the imaging system for adjusting it and for commanding capturing of pictures, andan image unit connected to the imaging system for receiving information representing captured pictures, the control unit comprising
a unit for determining settings of the imaging system, the settings determining unit finds an alignment position of an object plane of the optical system,a unit for evaluating pictures taken with the object plane in the alignment position to find a lateral offset between the two optical fiber ends, in particular between longitudinal axes of the two optical fiber ends or between center lines of claddings of the two optical fiber ends, seen along an optical axis,a unit for displacing the two optical fibers ends in relation to each other in a plane perpendicular to the optical axis along which the pictures are taken to make said lateral offset equal to a desired offset, anda unit for energizing the electrodes to splice the two optical fiber ends to each other; andthe settings determining unit to find the alignment position of the object plane of the optical system comprises:a collimated light source to illuminate a first side of one of the two optical fibers ends;a unit for setting the object plane in an initial position, wherein the initial position is selected to be at or at a relatively small distance of a second side of the one of the two optical fiber ends that faces the optical system and that then the object plane is displaced away from said one of the two optical fiber ends by one or more predetermined steps, in each predetermined step a picture being captured and evaluated to find a brightness of a truncated centrally located relatively bright area, a first position taken when the found brightness is larger than a predetermined threshold or in the middle of or inside a range of the predetermined steps in which the found brightness is larger than the predetermined threshold, wherein said predetermined threshold corresponds to the saturation level of an imaging sensor used to capture the pictures,a unit for evaluating said image in the captured picture taken at the first position, anda unit for displacing, based on the evaluating, the object plane from the first position along the optical axis to find the alignment position of the object plane where the alignment position of the object plane is found when the truncated centrally located relatively bright area has a width with a minimum value or deviates from a minimum value by at most a predetermined value, wherein the alignment position corresponds to a self-focus plane of said one of the two optical fiber ends, andwherein two charge-coupled device (CCD) elements are used to capture the image prior to transmitting the image to the control unit. |
