Rear focus zoom lens

Details Rear focus zoom lens Rear focus zoom lens

2006-01-10

2006-01-10

Spector, David N. (Department: 2873)

Optical: systems and elements

Lens

With variable magnification

C359S685000

Reexamination Certificate

active

06985303

ABSTRACT:
A rear focus zoom lens is disclosed that includes, in order from the object side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power and including a stop; a fourth lens group having negative refractive power; and a fifth lens group having positive refractive power. The second lens group and the third lens group are moved along the optical axis for zooming, the fourth lens group is moved along the optical axis for focusing, and the fourth lens group comprises a doublet consisting of a negative lens element and a positive lens element. The fifth lens group may have a specified configuration which includes an aspherical surface and that satisfies a specified condition which insures that aberrations are satisfactorily corrected over the entire range of zoom.

REFERENCES:
patent: 4189213 (1980-02-01), Iizuka
patent: 5764420 (1998-06-01), Yahagi
patent: 7-151972 (1995-06-01), None
patent: 2893119 (1999-03-01), None
patent: 2988164 (1999-10-01), None

Affiliated with

Also associated with

Rating

Rear focus zoom lens does not yet have a rating. At this time, there are no reviews or comments for this patent.

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

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-3530755