Imaging system with wavefront modification and method of increasing the depth of field of an imaging system

摘要

An imaging system (10) comprises an objective (1), an image detector (2) placed in an image plane of the objective, and a calculation unit (3) intended for executing a digital processing of an image captured by the detector. The objective is suitable for modifying a wavefront of a radiation which enters the system, so that an illumination on the detector which is produced by a source of the radiation is constant for a large interval of variation of a distance of separation of the source from the objective. The depth of field of the system is thus increased, and the calculation unit can be simplified by using a constant filter. The modification of the wavefront is created by a profile which is invariant under any rotations about the optical axis of the objective.