| 摘要 |
Targets for use with scanning light beam leveling/marking devices, are constructed with their elements assembled as unitary target structure. The lens and beam divider functions are provided by optical quality fresnel lenses attached to or formed on a polycarbonate block, these parts thus can be made essentially an integral element. These special fresnel lens which are optically equivalent of the input lens and beam dividing axicon, and the viewing screen diffuser function provided by a frosted viewing plate. A separate fresnel lens is mounted alongside the beam dividing lenses and functions to provide a reference image on the viewing screen. The optical path for the impinging light beam (after it is divided) may be transmitted directly through the body block, from the input to the view window, or through a reflector surface at a side of the block, the block body of the target functioning as a waveguide.
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