All-optical Imaging System with Extended Depth of Field

The Invention The All-optical imaging system allows for real time, on line imaging in any difficult focal conditions (i.e. movement, changing distances, problematic lighting/contrast ratios) without having to adjust or align the system. The system’s modified lens provides a high depth of field, namely, an extended region within which the image is kept in focus without the need for an auto focus mechanism or a post-processing step. Due to its large depth of field capability, the system can also be designed to capture images of objects located in non-congruent regions, something conventional optical systems cannot do. The All-optical imaging system is suitable for a wide variety of applications.
The Technological Innovation In this new technology the lens is corrected by a special phase mask, creating a system that tolerates significant variations in focus without post-processing.

The technology is based on a non-absorptive composite phase mask (CPM), consisting of several spatially multiplexed Fresnel Lenses (FL) that are used in conjunction with the primary lens of the system. When positioned in the pupil of an imaging system, the CPM increases the depth of field (DOF) significantly. Each individual FL provides perfect imaging for different object planes and essentially acts as a corrective lens with a slightly different focal length. The individual DOFs overlap slightly, resulting in a system with an extended DOF, albeit exhibiting a reduction of the image contrast and resolution. The system requires a single CCD detector.

Commercial Applications
§ Cellular phones with integrated cameras offer especially interesting opportunities for the integration of this technology. Cellphone cameras are used in circumstances where the distance from the object and the lighting conditions are not predefined or controlled.

§ This system is also suitable for image capture in machine vision systems, bar-code readers etc.

§ For digital cameras the All-optical imaging solution may need an electronic processing step that follows the image capture step to further improve the image quality.
Stage The All-optical Imaging System is ready to be implemented. It has been tested experimentally as well as in a simulation analysis (see references) and can be used for various applications. The combined lens is inexpensive for mass production manufacturing, making it attractive to OEM designers in industries requiring such imaging.
References Eyal Ben-Eliezer, Zeev Zalevsky, Emanuel Marom and Naim Konforti “All-optical extended depth of field imaging system” Pure Appl. Opt. 5 (2003), S164-S169.
Links Patent Pending Tech Transfer Officer Mr. Larry Loev Office: +972-3-6406544 Fax: +972-3-6406675 Mail: [email protected]

Inventor(s): Emanuel Marom

Type of Offer: Licensing

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