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:
Feb. 23, 1999
Filed:
Dec. 19, 1997
Masato Kato, Otsu, JP;
Minolta Co., Ltd., Osaka, JP;
Abstract
An eyepiece lens system has, from the pupil side and proceeding toward the object side, a first lens unit having a positive refractive power, a second lens unit having a positive refractive power, and a third lens unit having a positive refractive power. At least one of the first lens unit and the second lens unit has at least one aspherical surface, and the eyepiece lens system fulfills the following condition: ##EQU1## where, f represents a focal length of the entire eyepiece lens system; d.sub.0 represents an eye-relief; .phi..sub.1 represents a refractive power of the first lens unit; .phi..sub.2 represents a refractive power of the second lens unit; r.sub.1 represents a radius of curvature of a pupil side surface of the first lens unit; r.sub.3 represents a radius of curvature of a pupil side surface of the second lens unit; and r.sub.5 represents a radius of curvature of a pupil side surface of the third lens unit.
Data source: USPTO (United States Patent and Trademark Office) public patent records. Weekly synchronization. How IDiyas builds this profile