Large-aperture lens for low-illuminance imaging

Details Large-aperture lens for low-illuminance imaging Large-aperture lens for low-illuminance imaging

1998-03-25

1999-07-06

Sugarman, Scott J.

Optical: systems and elements

Lens

Reverse telephoto

359749, 359754, 359755, G02B 1304, G02B 964

Patent

active

059204362

ABSTRACT:
In a large-aperture lens for low-illuminance imaging, a Gauss type lens configuration is employed, and a negative lens having a predetermined refracting power is inserted in front of the front-side cemented lens, whereby back focus is secured while compactness is attained, without using an aspherical lens. Successively disposed from the object side are a biconvex lens L.sub.1, a positive meniscus lens L.sub.2 having a convex surface directed onto the object side, a negative lens L.sub.3 having a concave surface with a stronger curvature directed onto the image side, a positive meniscus lens L.sub.4 (cemented with lens L.sub.5) having a convex surface directed onto the object side, a negative meniscus lens L.sub.5 having a concave surface directed onto the image side, a biconcave lens L.sub.6 (cemented with lens L.sub.7) having a surface with a stronger curvature directed onto the object side, biconvex lenses L.sub.7 and L.sub.8 each having a surface with a stronger curvature directed onto the image side, and a positive meniscus lens L.sub.9 having a convex surface directed onto the object side. Assuming that the focal length of the whole system is f and the focal length of the third lens is f.sub.3, the conditional expression of 0.35<f/.vertline.f.sub.3 .vertline.<0.56 is satisfied.

REFERENCES:
patent: 3992085 (1976-11-01), Momiyama
patent: 4061421 (1977-12-01), Nakagawa
patent: 5623371 (1997-04-01), Hankawa
patent: 5796529 (1998-08-01), Park

Affiliated with

Also associated with

Rating

Large-aperture lens for low-illuminance imaging does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Large-aperture lens for low-illuminance imaging, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Large-aperture lens for low-illuminance imaging will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-903705