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:
Mar. 22, 2011
Filed:
Oct. 28, 2009
Yushi Ogino, Hyogo, JP;
Kunio Niwa, Kanagawa, JP;
Takayuki Yamazaki, Kanagawa, JP;
Panasonic Corporation, Osaka, JP;
Abstract
An eyepiece lens system for an electronic viewfinder, usable to be disposed on an optical axis between a reflective LCD of the viewfinder and a last optical surface of the viewfinder, the eyepiece lens system comprising: a first lens having a positive refractive index; a second lens having a negative refractive index; and a third lens having a positive refractive index, wherein the first lens, the second lens, and the third lens are disposed in this order from a side of the LCD to a side of the last optical surface, satisfying the conditions: 18 mm<f<20 mm, −18 mm<f<−16 mm, 18 mm<f<20 mm, 19 mm<f<21 mm, and 0≦HH'/f<+0.13 where fis a focal length of the first lens, fis a focal length of the second lens, fis a focal length of the third lens, f is a combined focal length of the first to the third lenses, and HH′ is distance in an optical axis direction between a rear principal point H and a front principal point H′.