The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jun. 30, 2015
Filed:
Aug. 15, 2013
Fujitsu Frontech Limited, Tokyo, JP;
Kozo Yamazaki, Inagi, JP;
Isao Iwaguchi, Inagi, JP;
FUJITSU FRONTECH LIMITED, Tokyo, JP;
Abstract
An illumination optical system for an image pickup apparatus includes a plurality of light sources arranged in a circular loop pattern and a prism plate shaped like a circular loop. the prism plate includes a prism surface at which illumination light from the light sources enters and on which a plurality of prism columns arranged in a circular loop pattern in a circumference direction of the prism plate are formed and an outgoing surface from which the illumination light is emitted. the prism surface includes a flat portion on at least one of a peak formed by each of the plurality of prism columns and a trough formed between the plurality of prism columns. the flat portion is substantially parallel to a tangential direction of the prism plate.