摘要 |
The invention relates to an apparatus for the determination of the focal distance of an optical imaging system comprising a first partly reflecting element and a second partly reflecting element which are arranged in the beam path at an angle to the optical axis such that a first portion of the light is reflected at the first element into a first light field, a second portion of the light is reflected at the second element into a second light field and a third portion of the light passes through both elements to form a third light field, and an optical detection device to register at least a part of an interference pattern in the overlap region of the first and second light fields. The invention furthermore relates to an optical imaging system comprising an apparatus in accordance with the invention for the determination of the focal distance and a laser scanner having an optical imaging system in accordance with the invention. Finally, the invention relates to a method for the determination of the focal distance of an optical imaging system with a variable focal distance.
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