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. 23, 1981
Filed:
Nov. 15, 1979
Applicant:
Inventor:
Hirohumi Matsuo, Asaka, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Primary Examiner:
Int. Cl.
CPC ...
G02B / ;
U.S. Cl.
CPC ...
350464 ;
Abstract
A photographic lens system such as a telescopic lens system adapted for use with a rear stop diaphragm in which the backfocus is about 0.3F, the F number is about F/2.8, the system is small in size and aberrations are well compensated for. Front and rear lens groups are provided with the front group including in order from the object positive, negative, positive and positive lenses while the rear group includes negative and positive lenses. Preferred focal lengths, radii of curvature, refractive indices, and Abbe numbers for each of the lenses are disclosed.