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:
Nov. 21, 2017
Filed:
Jan. 19, 2016
Ricoh Imaging Company, Ltd., Tokyo, JP;
Moriyasu Kanai, Saitama, JP;
RICOH IMAGING COMPANY, LTD., Tokyo, JP;
Abstract
An eyepiece optical system includes a focal-plane plate, having a positive refractive power on one side and a diffusion surface on the other side thereof; a reflector which reflects light rays of an object image, formed on the diffusion surface, a predetermined number of times; an optical lens group, by which the object image is observed, in that order along an optical path from the object side to the viewing side; and a condenser lens element, having a positive refractive power, provided between the focal-plane plate and the reflector, the condenser lens element having an aspherical surface formed on at least one side thereof. At least one of the aspherical surface of the condenser lens element has a profile, when viewed macroscopically, such that the positive refractive power thereof increasingly weakens with respect to a direction away from the optical axis.