Title:
【発明の名称】電子撮像装置用レンズ
Document Type and Number:
Japanese Patent JP2001504949
Kind Code:
A
Abstract:
PCT No. PCT/US97/20144 Sec. 371 Date May 25, 1999 Sec. 102(e) Date May 25, 1999 PCT Filed Nov. 12, 1997 PCT Pub. No. WO98/23988 PCT Pub. Date Jun. 4, 1998A lens system for an electronic system has two lenses. The first lens (S1/S2) has a negative power, and the second lens (S4/S5 or S5/S6) has a positive power and is spaced from the first lens (S1/S2) by a distance of at least a quarter of the focal length of the lens system. In one embodiment (FIG. 3), the second lens (S4/S5) is a refractive-diffractive hybrid lens; in which case both the first and the second lenses (S1/S2 and S4/S5) can be composed of acrylic, and can have only spherical and conic surfaces. In other embodiments (FIG. 1, 2, 4), the first lens (S1/S2) has a higher dispersion than the than the second lens (S4/S5 or S5/S6); for example, the first lens (S1/S2) is composed of styrene, and the second lens (S4/S5 or S5/S6) is composed of acrylic. In this case, the first lens (S1/S2) can have a spherical surface and a general aspherical surface, and the second lens (S5/S6) can have conic surfaces (FIG. 1, 2); or both of the first and second lenses (S1/S2 and S4/S5) can have a spherical surface, and a conic surface (FIG. 4).
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Inventors:
Kreizer, Melvin H
Application Number:
JP52466298A
Publication Date:
April 10, 2001
Filing Date:
November 12, 1997
Export Citation:
Assignee:
US Precision Lens Inc.
International Classes:
G02B9/04; G02B9/10; G02B13/04; G02B13/18; G02B27/00; (IPC1-7): G02B9/10; G02B13/18
Attorney, Agent or Firm:
Seiji Yanagida (1 person outside)