Fish eye lens system
First Claim
Patent Images
1. A five element fish eye lens system comprising from the object to the image side:
- a first meniscus shaped lens (L1) of negative refractive power curved towards the object,a second lens (L2) of negative refractive power curved towards the object,a third positive meniscus lens (L3) of positive refractive power curved towards the object,an aperture stop (B),a fourth lens (L4) of positive refractive power curved towards the image, anda fifth meniscus shaped lens (L5) of negative refractive power curved towards the image.
0 Assignments
0 Petitions
Accused Products
Abstract
A high performance medium speed fish eye lens system is provided capable of compensating all aberrations except the distortion up to an aperture ratio of 1:4. The lens system includes a first negative meniscus shaped lens convex to the object, a second negative lens curved towards the object, a third positive lens curved towards the object, an aperture stop, a fourth positive lens curved towards the image and a fifth meniscus shaped negative lens convex to the image. The fourth and the fifth lens are close together or cemented. An optical filter can be inserted between the third and the fourth lens.
29 Citations
21 Claims
-
1. A five element fish eye lens system comprising from the object to the image side:
-
a first meniscus shaped lens (L1) of negative refractive power curved towards the object, a second lens (L2) of negative refractive power curved towards the object, a third positive meniscus lens (L3) of positive refractive power curved towards the object, an aperture stop (B), a fourth lens (L4) of positive refractive power curved towards the image, and a fifth meniscus shaped lens (L5) of negative refractive power curved towards the image. - View Dependent Claims (2, 3)
-
-
4. A five element fish eye lens system comprising five lens elements from the object to the image side:
-
a first meniscus shaped lens (L1) of negative refractive power made from a glass of an Abbe'"'"'s number higher than 45 curved towards the object, a second lens (L2) of negative refractive power made from a glass of an Abbe'"'"'s number higher than 45 and curved towards the object, said second lens forming together with said first lens (L1) a first lens group, which has a resulting focal length of -0.5 to -1.2 f, a single third lens (L3) of positive refractive power curved towards the object and made from a glass of a relatively high refraction index and low Abbe'"'"'s number, said third lens having a focal length of 1.5 to 2.5 f, an aperture stop, a fourth lens (L4) of positive refractive power curved towards the image and made from a glass of an Abbe'"'"'s number higher than 52, having a radius of -0.35 to -0.7 f on its surface facing the image side, and a fifth meniscus shaped lens (L5) of negative refractive power made from a glass of a refraction index higher than 1.65 and an Abbe'"'"'s number less than 30, said fifth lens having a radius of -0.35 to -0.7 f on its surface facing the object side and a radius of -0.8 to -1.4 f on its surface facing the image side, said fourth lens and said fifth lens forming a lens group, wherein f represents the effective focal length of the entire lens system. - View Dependent Claims (5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
-
-
20. A fish eye lens system comprising six lens elements in three groups in the following manner, from the object to the image side:
-
a first meniscus shaped lens (L1) of negative refractive power curved towards the object, a second lens (L2) of negative refractive power curved towards the object and forming--together with the first lens (L1)--a first lens group (G1), a third positive meniscus shaped lens (L3) of positive refractive power curved towards the object, a fourth positive meniscus lens (L4) of positive refractive power curved towards the object and forming--together with the third lens (L3)--a second lens group (G2), an aperture stop (B), a fifth lens (L5) of positive refractive power curved towards the image, and a sixth meniscus shaped lens (L6) of negative refractive power curved towards the image and forming--together with the fifth lens (L5)--a third lens group (G3). - View Dependent Claims (21)
-
Specification