| 摘要 |
An apparatus for the relative alignment of two objects is described which comprises at least one light source, a photosensitive detection system and two carriers which are made of a translucent material or an opaque material and on which have been formed patterns of areas of an opaque material or a translucent material respectively. It is shown that a direct indication of the direction of a deviation is obtainable by using a special embodiment in which the patterns of the carriers each consist of two regular component patterns, one of the component patterns on one of the carriers being staggered with respect to the other component pattern on this carrier through a small distance in the direction of width of the areas, the region to one side of one of the component patterns and that to the other side of the other component pattern on this carrier being made of an opaque material, while with each of the said component patterns there is associated a separate detector.
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