Title:
焦点拡張光学系及びEDoF撮像システム
Document Type and Number:
Japanese Patent JP5390046
Kind Code:
B2
Abstract:
A recognition rate for characters or the like, captured in a near view image, of software is improved without reduction in depth of field. A focus extending optical system (11) has optical lenses (11) and a focus extender. The optical lenses form an image of light, from an obj ect (14), on an image sensor. The focus extender adjusts a wavefront so as to change an image-forming position of the optical lenses (11) in accordance with a distance from an optical axis (L0) 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 (12). The second MTF is an MTF at a spatial frequency of 1/4 of the Nyquist frequency.
Inventors:
Kishine Keinobu
Application Number:
JP2013507353A
Publication Date:
January 15, 2014
Filing Date:
March 13, 2012
Export Citation:
Assignee:
FUJIFILM Corporation
International Classes:
G02B13/00; G02B13/18; G03B7/04; G06V30/142; G06V30/10
Domestic Patent References:
| JP2010109625A | ||||
| JP2008245266A |
Foreign References:
| WO2009061519A1 | ||||
| WO2009106996A1 | ||||
| WO2008105431A1 |
Attorney, Agent or Firm:
Kazunori Kobayashi