| 摘要 |
<p>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.</p> |
