Optical: systems and elements – Lens – With variable magnification
Patent
1995-06-28
1997-04-22
Fields, Carolyn E.
Optical: systems and elements
Lens
With variable magnification
359792, 359749, G02B 912
Patent
active
056233710
ABSTRACT:
The present invention provides a photographic lens system capable of close-up photography in which various aberrations such as spherical aberration and coma, and curvature of field are concurrently corrected in a well-balanced state and which is relatively bright as expressed by an F-number of about 2.8, and is characterized by comprising a first lens group G.sub.1 which includes a front sub-group G.sub.1F having positive refracting power and a rear sub-group G.sub.1R having negative refracting power and has positive refracting power in its entirety, a second lens group G.sub.2 having positive refracting power in its entirety, and a third lens group G.sub.3 having positive refracting power in its entirety, the lens of the front sub-group G.sub.1F nearest to the image side being concave on the image side and the lens of the rear sub-group G.sub.R nearest to the object side being convex on the object side, and also characterized in that when the macro lens system is focused from the object point at infinity on the object point at a shorter distance, the first lens group G.sub.1 including the front and rear lens sub-groups G.sub.1F and G.sub.1R and the second lens group G.sub.2 are moved toward the object side while the third lens group G.sub.3 is fixed.
REFERENCES:
patent: 4178076 (1979-12-01), Tsuji et al.
patent: 4807983 (1989-02-01), Matsushita
patent: 4871243 (1989-10-01), Ogawa et al.
patent: 4986643 (1991-01-01), Moriyama
patent: 5007720 (1991-04-01), Hamanishi
patent: 5331465 (1994-07-01), Miyano
Fields Carolyn E.
Olympus Optical Co,. Ltd.
LandOfFree
Macro lens 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 Macro lens system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Macro lens system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-345402