US 2010/0060997 A1 · Illumination lens and endoscope illuminating optical system

Abstract

An endoscope illuminating optical system includes an illumination lens having a positive power. Illumination light rays parallel to each other emitted from an optical fiber bundle enter an incident surface of the illumination lens. The incident surface of the illumination lens is aspherical, and has a reference position vertical to the optical axis. The reference position is the most projecting portion on the incident surface. A shape of the incident surface is expressed by an equation of D=F(H). “H” is a height from the optical axis (0≦H≦Hmax), and “D” is a depth from a reference plane. The reference plane is vertical to the optical axis. The reference position is on the reference plane. A first-order differential value of the function F(H) is more than 0, and a second-order differential value of the function F(H) is 0 at a particular height Hi (0<Hi<Hmax).

Claims10

Dependent claims

An illumination lens comprising:

an aspherical incident surface having a reference position intersecting an optical axis, said reference position being the most projecting portion of said incident surface, wherein
a shape of said incident surface is expressed by an equation of D=F(H), where H is a height from said optical axis and falls in a range of 0≦H≦Hmax, and D is a depth from a reference plane which is vertical to said optical axis and on which said reference position is located, and
a first-order differential value of the function F(H) is 0 or more, and a second-order differential value of the function F(H) is 0, when said H is a particular height Hi in a range of 0<Hi<Hmax.

Dependencies are inferred from the claim text.

Illumination lens and endoscope illuminating optical system

Life of this patent

Illumination lens and endoscope illuminating optical system

Life of this patent

Abstract

Claims10