Optical: systems and elements – Lens – With variable magnification
Patent
1990-12-06
1992-10-13
Sugarman, Scott J.
Optical: systems and elements
Lens
With variable magnification
358685, 358713, G02B 1514, G02B 1318
Patent
active
051556308
ABSTRACT:
The present invention provides a compact zoom lens having a zooming ratio of six (6) to eight (8) and an F-number of 1.4 to 1.6, and comprising from the object side; a first lens unit of a positive refractive power and consisting of, from the object side, a first negative meniscus lens element convex to the object side, a second positive lens element, located at the image side of the first negative meniscus lens element with having an air space therebetween, having a stronger refractive surface on its object side surface; a second lens unit of a negative refractive power and consisting of, from the object side, a third negative lens element having a stronger refractive surface of its image side surface, and a fourth positive lens element, located at the image side of the third negative lens element with having an air space therebetween, said second lens unit including an aspheric surface; a third lens unit of a positive refractive power and consisting of a single positive lens element having an aspheric surface; and a fourth lens unit of a positive refractive power and including a positive lens element and a negative lens element; and the second lens unit being shiftable in the zooming operation and at least one of the first, third and fourth lens unit being also shiftable in the zooming operation.
REFERENCES:
patent: 4818083 (1989-04-01), Mihara
patent: 4859042 (1989-08-01), Tanaka
patent: 4906079 (1990-03-01), Mihara et al.
Minolta Camera Co. Ltd.
Sugarman Scott J.
LandOfFree
Zoom 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 Zoom lens system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Zoom lens system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1305676