Title:
FOCUS EXTENDING OPTICAL SYSTEM AND EDOF IMAGING SYSTEM
Document Type and Number:
WIPO Patent Application WO/2012/132870
Kind Code:
A1
Abstract:
The present invention increases the recognition rate by software of characters or the like pictured in a close-range-view image without loss of depth of field. A focus extending optical system (11) has: an optical lens (11) that, at an imaging element, forms an image of light from a subject (14); and a focus extender that extends the focal range by adjusting the wavefront in a manner so that the image formation position of the optical lens (11) is changed in accordance with distance from the optical axis (L0). Furthermore, when the MTF at the spatial frequency that is 1/2 the Nyquist frequency of the imaging element (12) is the first MTF and the MTF at the spatial frequency that is 1/4 the Nyquist frequency is the second MTF, the condition is satisfied that the second MTF is at a value that is no greater than three times the first MTF.
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Inventors:
KISHINE YASUNOBU (JP)
Application Number:
PCT/JP2012/056366
Publication Date:
October 04, 2012
Filing Date:
March 13, 2012
Export Citation:
Assignee:
FUJIFILM CORP (JP)
KISHINE YASUNOBU (JP)
KISHINE YASUNOBU (JP)
International Classes:
G02B13/00; G02B13/18; G03B7/04; G06V30/142; G06V30/10
Domestic Patent References:
| WO2009061519A1 | 2009-05-14 | |||
| WO2009106996A2 | 2009-09-03 | |||
| WO2008105431A1 | 2008-09-04 |
Foreign References:
| JP2010109625A | 2010-05-13 | |||
| JP2008245266A | 2008-10-09 | |||
| JP2010213274A | 2010-09-24 | |||
| JP2007206738A | 2007-08-16 | |||
| JP2006094471A | 2006-04-06 |
Other References:
See also references of EP 2693249A4
Attorney, Agent or Firm:
KOBAYASHI, KAZUNORI (JP)
Kazunori Kobayashi (JP)
Kazunori Kobayashi (JP)
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Claims: