| 摘要 |
A method for positioning an array with periodic structures, for forming an image thereon, comprises the following steps: (i) producing a light beam along fast-scan axis; (ii) translating the array in a direction substantially perpendicular to the fast-scan axis; (iii) detecting the light beam alternatively by a pair of detectors, the detectors being located near opposite edges of the array along the fast-scan axis; (iv) providing substantially periodic signals by the pair of detectors in accordance with their detection of the light beam; (v) determining relative phases of the periodic signals, the relative phases corresponding to misalignment of the array; (vi) sensing phases of the periodic signals and rotating the array such that the long axes of the periodic structures are substantially parallel to the fast-scan axis. According to another aspect of the present invention, an apparatus for locating an array having a periodic structure, comprises: (i) a stage rotatably supporting the array; (ii) a light source providing a light beam; (iii) a scanner scanning the light beam across the array; (iv) two detectors, the two detectors alternatively detecting the scanned light beam while the array is translated in a slow scan direction, each of the two detectors providing periodic signals in response to the detection; (v) an analyzer determining relative phases of the periodic signals from each of the two detectors, the analyzer outputting signals based on the relative phases, the signals being capable of activating rotational motion of the stage until the array is in proper orientation.
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