Optical system provided with a device for augmenting its depth of field

US8331030B2 · kind B2 · utility

Assignee

• DXO LABS · FR

Inventors

• Bruno Liege · Boulogne, FR
• Regis Tessieres · Paris, FR
• Frederic Guichard · Santa Monica, US
• Etienne Knauer · Boulogne, FR
• Hoang-Phi Nguyen · Paris, FR

Key dates

• Filing date: Jul 9, 2008
• Grant date: Dec 11, 2012
• Expiry date: Jan 22, 2029

Classification

• Technology area (CPC G): Physics
• CPC primary: G02B27/40
• WIPO field: Optics
• WIPO sector: Instruments

Abstract

In order to increase the depth of field of an optical system, there is provision to add a phase object, interposed between an object (O) to be imaged and an image plane (8) of the optical system. The phase object is interposed although a chromatic aberration of the system is not yet corrected. After interposition, the measured optical signal is corrected complementarily so as to eliminate the chromatic aberrations therefrom. It is shown that if a parameter of the expansion of the expression, a function of pupil dependency, that the difference in path length of the optical system possesses a significant value of higher order than that of the defocus, then an increase in the depth of field is obtained.