US 2003/0197802 A1Published application

Electronic imaging system

AssigneeOlympus Optical Co., Ltd.

InventorShigeru Kato

Life of this patent

Estimating the term…

Loading patent…

Abstract

The invention relates to an electronic imaging system wherein an image pickup device is horizontally located while ensuring the space for a reflective member thereby achieving height, length and cost reductions. The imaging system comprises a taking lens and an image pickup device. The taking lens comprises a front lens group G1 consisting of a negative lens component and a positive lens component and having positive refracting power and a rear lens group G2 consisting of a negative lens element and a positive lens element and having positive refracting power, with an aperture stop S interposed between the front lens group G1 and the rear lens group G2. The taking lens satisfies conditions (1) and (2). 2.8<fB/IH<4.5 (1) 2<SF<3 (2) Here fB is back focus of the taking lens, IH is a length that is half the diagonal length of the effective plane of the electronic image pickup device, and SF is a shape factor for the negative lens component in the front lens group.

Claims14

Dependent claims

An electronic imaging system comprising a taking lens and an electronic image pickup device located on an image side thereof, wherein:

the taking lens comprises a front lens group consisting of a negative lens component and a positive lens component and having positive refracting power and a rear lens group consisting of, in order from an object side thereof, a negative lens element and a positive lens element and having positive refracting power, with an aperture stop interposed between the front lens group and the rear lens group, and
conditions (1) and (2) are satisfied:
2.8<fB/IH<4.5 (1)2<SF<3 (2)
where fB is a length, as calculated on an air basis, of a back focus of the taking lens, IH is a length that is half a diagonal length of an effective plane of the electronic image pickup device, and SF is a shape factor (RF+RR)/(RF−RR) for the negative lens component in the front lens group where RF and RR are radii of curvature of the object side and image side of the negative lens component in the front lens group, respectively.

1 more element

Dependencies are inferred from the claim text.

Facts

Application: 10/417,131Filed 17 Apr 2003
Priority: JP 2002-11777719 Apr 2002
Published: 23 Oct 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G02B 13/005
Characterised by the lens design: having spherical lenses only
G02B 13/004
Having at least one aspherical surface: having four lenses
G02B 13/006
Employing a special optical element: at least one element being a compound optical element, e.g. cemented elements
G02B 13/04
Optical objectives specially designed for the purposes specified below: reversed telephoto objectives