Patent Number: 8,743,266

Title: Focus extending optical system and EDOF imaging system

Abstract: A focus extending optical system has optical lenses and a focus extender. The optical lenses form an image of light, from an object, on an image sensor. The focus extender adjusts a wavefront so as to change a position of the image, formed by the optical lenses, in accordance with a distance from an optical axis and thereby extends a focus range. The focus extending optical system satisfies a condition that a value of a second MTF is less than or equal to three times a value of a first MTF. The first MTF is an MTF at a spatial frequency of 1/2 of a Nyquist frequency of the image sensor. The second MTF is an MTF at a spatial frequency of 1/4 of the Nyquist frequency.

Inventors: Kishine; Yasunobu (Saitama, JP)

Assignee: Fujifilm Corporation

International Classification: H04N 5/225 (20060101); H04N 5/232 (20060101); G03B 13/00 (20060101)

Expiration Date: 2022-06-03 0:00:00