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Patent Searching and Data


Title:
OPTICAL FILTER, LIGHT VOLUME ADJUSTING DEVICE AND IMAGE PICKUP DEVICE HAVING SAME
Document Type and Number:
WIPO Patent Application WO/2013/088675
Kind Code:
A1
Abstract:
[Problem] To suppress the occurrence of a high luminance ghost caused by diffraction at the edges of an optical filter. [Solution] Provided is an optical filter (20) having a filter edge section (20a) which is the boundary between a region that covers at least a portion of the luminous flux that forms a subject image and in which the luminous flux passes through the optical filter, and a region in which the luminous flux does not pass through the optical filter. The filter edge section (20a) has an uneven shape having an outer edge shape formed by a continuous curved line in which, in the direction that the boundary extends, protrusions (20b) and recesses (20c) run together in an alternating manner. On the curved line, if an angle formed by a tangent line (LM) of an intermediate point (M) between the vertex (T) of one protrusion and the nadir (B) of one recess adjacent to the protrusion, and a tangent line (LT) of the vertex (T), is designated as Өa, which is an angle that grows larger the farther intermediate point (M) is from the vertex (T), the curved line has a portion that satisfies the condition Өa≥60°.

Inventors:
SUZUKI KAZUO (JP)
OKADA RYOKO (JP)
HORIUCHI AKIHISA (JP)
ABE HIROFUMI (JP)
MIYAZAWA NOBUYUKI (JP)
Application Number:
PCT/JP2012/007784
Publication Date:
June 20, 2013
Filing Date:
December 05, 2012
Export Citation:
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Assignee:
CANON DENSHI KK (JP)
CANON KK (JP)
International Classes:
G02B5/00; G03B9/02; G03B11/00
Foreign References:
JP2007065109A2007-03-15
JP2007090656A2007-04-12
JP2003004916A2003-01-08
JPH05281590A1993-10-29
JP2007178823A2007-07-12
JP2008233356A2008-10-02
JP2008065227A2008-03-21
JP2007065109A2007-03-15
JP2007178823A2007-07-12
JP2009186673A2009-08-20
Other References:
See also references of EP 2793060A4
Attorney, Agent or Firm:
FUJIMOTO, RYOSUKE (JP)
Ryosuke Fujimoto (JP)
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Claims: