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:
May. 19, 1987
Filed:
Nov. 25, 1985
Applicant:
Inventor:
Takayuki Itoh, Tokyo, JP;
Assignee:
Asahi Kogaku Kogyo Kabushiki Kaisha, Tokyo, JP;
Attorney:
Primary Examiner:
Assistant Examiner:
Int. Cl.
CPC ...
G02B / ; G02B / ;
U.S. Cl.
CPC ...
350454 ;
Abstract
A telephoto macro lens system includes, in order from the object side, a first lens group having a positive focal length and a second lens group having a negative focal length. The first lens group is composed of a first subgroup (1a) including a positive lens group and a negative meniscus lens and a second subgroup (1b) including a negative lens having a divergent surface on the object side. The second lens group is composed of a third subgroup (2a) having a large negative refractive power and a positive unitary lens (2b) spaced from the third subgroup. The lens system is so constructed as to satisfy the following conditions: