Optical: systems and elements – Lens – With variable magnification
Patent
1996-01-31
1997-12-02
Nelms, David C.
Optical: systems and elements
Lens
With variable magnification
359684, 359687, G02B 1514
Patent
active
056942532
ABSTRACT:
A compact zoom lens has a high zoom ratio that is suitable for a single lens reflex camera. Embodiments of the zoom lens include, in order from the object side, a first lens unit of positive refractive power, a second lens unit of negative refractive power, and a third lens unit of positive refractive power, that all move toward the object during zooming from the maximum wide-angle state to the maximum telephoto state, with the distance between the first lens unit and the second lens unit increasing, and the distance between the second lens unit and the third lens unit decreasing; and wherein various conditions are satisfied. The zoom lens may include a focal length shorter than the length of the diagonal of the effective picture plane and a focal length longer than three times the length of the diagonal of the effective picture plane, and includes a fourth lens unit of positive refractive power on the image side of the third lens unit, wherein during zooming from the maximum wide-angle state to the maximum telephoto state, the distance between the third lens unit and the fourth lens unit decreases with the fourth lens unit also moving toward the object.
REFERENCES:
patent: 4632519 (1986-12-01), Takahashi
patent: 4657351 (1987-04-01), Mori
patent: 4890904 (1990-01-01), Ito
patent: 5337187 (1994-08-01), Fukino et al.
Nelms David C.
Nikon Corporation
Schwartz Jordan M.
LandOfFree
High zoom ratio 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 High zoom ratio zoom lens, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and High zoom ratio zoom lens will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-806123