Zoom optical system

Details Zoom optical system Zoom optical system

1998-12-23

2000-02-15

Epps, Georgia

Optical: systems and elements

Lens

With variable magnification

359681, 359682, 359686, G02B 1514

Patent

active

060259604

ABSTRACT:
The invention provides a compact zoom optical system which can be reduced in terms of the lens length upon collapsing, albeit having a zoom ratio as 3 or greater. The zoom optical system comprises a first lens group G1 having positive power, a second lens group G2 having positive power and a third lens group G3 having negative power. For zooming from the wide-angle end to telephoto end of the system, the lens groups move together toward the object side while the space between the first group G1 and the second group G2 becomes wide and the space between the second group G2 and the third group G3 becomes narrow. The second group G2 comprises a front lens subgroup G.sub.2A having negative power and a rear lens subgroup G.sub.2B, between which an aperture stop S is located. At least one aspheric surface is used in the rear subgroup G.sub.2B in the second group G2. The optical system satisfies 0.4<f.sub.W /f.sub.1G <1.0 where f.sub.W is the focal length of the optical system at the wide-angle end and f.sub.1G is the focal length of the first group G1.

REFERENCES:
patent: 4978204 (1990-12-01), Ito
patent: 4983027 (1991-01-01), Kojima et al.
patent: 5315439 (1994-05-01), Ito
patent: 5363243 (1994-11-01), Takayuki et al.
patent: 5566026 (1996-10-01), Yoon
patent: 5640276 (1997-06-01), Ogata

Affiliated with

Also associated with

Rating

Zoom optical system does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Zoom optical system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Zoom optical system will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-1910589