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:
Jul. 31, 2007
Filed:
Oct. 22, 2003
Yoji Kubota, Nagano, JP;
Toshio Matsui, Nagano, JP;
Yoji Kubota, Nagano, JP;
Toshio Matsui, Nagano, JP;
Nagano Optics Laboratory Corporation, Nagano, JP;
Abstract
An imaging lens () comprising, arranged sequentially from the object side, a positive-meniscus first lens () with its convex plane facing the object side, a negative-power-meniscus second lens (), and a positive-power third lens (), the second and third lenses () functioning as correction lenses. The first lens () has a strong power, and both the second and third lenses () are aspherical on opposite planes. When the synthetic focal distance of the imaging lens is f, the focal distance of the first lens f1, the distance from the incident surface on the object side to the imaging surface of the first lens () Σd, and the Abbe number of the second lens √d2, the following conditional expressions are satisfied. 0.50<f1/f<1.5 (1) 0.50<Σd/f<1.5 (2) 50>√d2 (3). Accordingly, a small, low-cost imaging lens capable of high-quality imaging can be realized.