Wide-angle objective for endoscopes
First Claim
1. A wide-angle objective for an endoscope, said objective having a distal side facing an object and an image side, a meniscus being located at the distal side with a concave first surface facing towards the object, another optical component being of the meniscus, the improvements comprising said meniscus being a distal meniscus with said first surface having a first radius r1, said distal meniscus having a second surface with a second radius r2 facing toward said another optical component, said another optical component being a proximal meniscus having a first surface with a radius r3 facing toward the distal meniscus and a second surface with a radius r4 facing towards said image side of the objective, said objective having a field of view angle α
- and an overall focal length of F, said distal meniscus having a focal length of f1 and said proximal meniscus having a focal length f2, and the proximal and distal menisci having the following dimensions;
##EQU2## wherein nd is an index of refraction for a wavelength of 580 nm; and
Vd is an abbe coefficient for a wavelength of 580 nm.
2 Assignments
0 Petitions
Accused Products
Abstract
A wide-angle objective for endoscopes, in particular for video endoscopes comprises fibre image conductors or CCD image transducers, in which known instruments are taken as a basis, in which a distally positioned objective comprises a meniscus lens with its concave surface facing towards the object, as well as another optical component located on the image side. To secure an uncomplicated structure, adequate image quality, a wide object field angle and short structural length, the image-side optical component is also produced as a meniscus lens.
-
Citations
6 Claims
-
1. A wide-angle objective for an endoscope, said objective having a distal side facing an object and an image side, a meniscus being located at the distal side with a concave first surface facing towards the object, another optical component being of the meniscus, the improvements comprising said meniscus being a distal meniscus with said first surface having a first radius r1, said distal meniscus having a second surface with a second radius r2 facing toward said another optical component, said another optical component being a proximal meniscus having a first surface with a radius r3 facing toward the distal meniscus and a second surface with a radius r4 facing towards said image side of the objective, said objective having a field of view angle α
- and an overall focal length of F, said distal meniscus having a focal length of f1 and said proximal meniscus having a focal length f2, and the proximal and distal menisci having the following dimensions;
##EQU2## wherein nd is an index of refraction for a wavelength of 580 nm; and
Vd is an abbe coefficient for a wavelength of 580 nm. - View Dependent Claims (2, 3, 4, 5, 6)
- and an overall focal length of F, said distal meniscus having a focal length of f1 and said proximal meniscus having a focal length f2, and the proximal and distal menisci having the following dimensions;
Specification