Patent ID: 7511895

Claim:
An imaging system for recording an extended depth of field, comprising: a multifocal imaging subsystem including an optical imaging element having a maximum radius, R, that produces an intermediate image of an object, wherein the multifocal imaging subsystem has a controlled amount of spherical aberration that imparts a purposeful blur to the intermediate image that is substantially uniform over the focal range of the multifocal imaging subsystem, and a phase plate that produces the controlled amount of spherical aberration, located at an aperture stop of the subsystem; a digital processing system that receives the blurred, intermediate image and calculates a non-blurred, recovered image; and, provided a criteria is met, the multifocal imaging subsystem including a central obscuration having a radius, Î´R, wherein the criteria is that â…™â‰¦Î´R/R<1, otherwise Î´R being zero and the central obscuration is absent.