Three-group zoom lens

Optical: systems and elements – Lens – With variable magnification

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C359S680000

Reexamination Certificate

active

07046452

ABSTRACT:
A three-group zoom lens includes, in order from the object side, first, second and third lens groups having negative, positive and positive refractive power, respectively. During zooming from the wide-angle end to the telephoto end, the second lens group moves monotonically toward the object side while moving closer to the first lens group and farther from the third lens group, and the first and third lens groups reverse directions to define curved paths. The third lens group is closer to the object side at the wide-angle end and moves toward the object side for close focusing. The focal lengths of the zoom lens and its lens groups, the zoom ratio, the length of the zoom lens, and the half-field angle at the wide-angle end satisfy certain conditions in order to achieve a zoom ratio of at least three with favorable correction of aberrations.

REFERENCES:
patent: 6618210 (2003-09-01), Noguchi et al.
patent: 6757111 (2004-06-01), Takeuchi et al.
patent: 6781768 (2004-08-01), Minefuji
patent: 10-133115 (1998-05-01), None
patent: 2001-296476 (2001-10-01), None
patent: 2003-35868 (2003-02-01), None

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Three-group 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 Three-group zoom lens, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Three-group zoom lens will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3581653

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.