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Patent Searching and Data


Title:
IMAGE PICKUP LENS
Document Type and Number:
Japanese Patent JP2001100090
Kind Code:
A
Abstract:

To hold high telecentricity while securing a wide field angle and making an optical system small-sized, to secure sufficient back focus length, and further facilitate manufacturing.

A 1st lens 1 composed of a concave lens, a stop 3, and a 2nd lens 2 composed of a convex lens are arrayed in order from the object side and the 1st lens 1 and 2nd lens 2 meet the conditions of (1) 1.2f2<d2<1.6f2, (2) (f2)2/S≥2.2f1, and (3) 2f1< f1 <3f1, where f1 is the focal length of the 1st lens 1, 2 the focal length of the 2nd lens 2, f1 the focal length of the whole optical system, d2 the lens interval between the 1st lens 1 and 2nd lens 2, and S the distance from the front focus position of the 2nd lens 2 to the aperture stop 3.


Inventors:
Saito, Tomohiro
Kaneko, Isamu
Application Number:
JP1999000276285
Publication Date:
April 13, 2001
Filing Date:
September 29, 1999
Export Citation:
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Assignee:
ENPLAS CORP
International Classes:
G02B9/10; G02B13/04; G02B13/22; (IPC1-7): G02B9/10; G02B13/04