摘要 |
An optical subsystem (14) for use in an electronic imaging system (10) utilizes a spatial filter (20) having a concentric optical path profile for removing unwanted structures in the optically formed image. In a first embodiment, the filter (20) includes an axisymmetric conical surface (24) formed on an optical substrate (22) to provide a light path modifying profile designed to achieve a desired circular point spread function in an image plane (16). Other embodiments include an elliptical/conical profile, and an axisymmetric, concentric ring profile. The filter profile may be single-point diamond turned into a flat filter substrate, or can be combined/integrated with the profile of an existing optical system element, such as lens (18). The present invention further provides a method for removing unwanted artificial image structures by generating an imaging system point spread function which is a hollow, closed path.
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