Highly corrected relay system
A highly corrected relay system for medical endoscopes or the like is provided. The system includes a plurality of bonded lenses that are selected to provide color correction from the blue region of the spectrum through to the near infrared region of the spectrum. The system allows co-located visible and near infrared images to be resolved on a single detector.
1. A highly corrected relay system for an endoscope, comprising:
a plurality of bonded lenses, wherein the plurality of bonded lenses is selected to provide color correction from the blue region of the spectrum through to the near infrared region of the spectrum, wherein light from the blue region of the spectrum through to the near infrared region of the spectrum follows a same optical path, and wherein the system allows co-located visible and near infrared images to be resolved on a single detector; and
a symmetrical pair of rod lens assemblies, wherein each rod lens assembly includes
a first bi-convex lens;
a second plano-concave lens;
a third elongated plano/piano rod lens;
a fourth plano-convex lens; and
a fifth meniscus lens.
2. The highly corrected relay system of claim 1 , wherein the color correction is provided from approximately 400 nm to approximately 900 nm.
3. The highly corrected relay system of claim 1 , wherein the pair of rod lens assemblies is arranged around an air space containing a centered pupil and aperture stop position.
4. A highly corrected relay system for an endoscope providing color correction from the blue region of the spectrum through to the near infrared region of the spectrum, and wherein the system allows co-located visible and near infrared images to be resolved on a single detector, comprising a symmetrical pair of rod lens assemblies including a plurality of lens elements and an aperture location, each element having a lens surface defined by a radius of curvature (r), a thickness (t), an index of refraction (n), and a dispersion value (v), the plurality of lens elements being spaced from each other, an object to be viewed and an image of the object by a distance (h) and wherein the assembly satisfies two or more of the following conditions:
1000<r4/r2 or r4=r2=approximately infinity;
−0.56<r3/r9<−0.81;
0.9<r8/r9<1.1 or r8=r9;
0.9<r10/r11<1.1 or r10=r11;
0.7<(h1+h2)/(h3+h4)<1.1;
0.95<h1+h2+h3+h4+T1+T2+T3+T4+T5+T6<f/1.02;
1.71<nL1, nL2, nL5, nL6<1.79; and
1.67<nL3, nL4<1.81
Where: r1 represents a radius of curvature of the collimated side surface of a first lens element; r2 represents a radius of curvature of an image side surface of a first lens element; r3 represents a radius of curvature of an collimated side surface of a second lens element; r4 represents a radius of curvature of an image side surface of the second lens element; r8 represents a radius of curvature of an object side surface of a fifth lens element; r9 represents a radius of curvature of an object side surface of the fifth lens element; T1 represents a thickness of the first lens element; T2 represents a thickness of the second lens element; T3 represents a thickness of the third lens element; T4 represents a thickness of the fourth lens element; T5 represents a thickness of the fifth lens element; nL1 represents an index of refraction of the first lens element; nL2 represents an index of refraction of the second lens element; n3 represents an index of refraction of the third lens element; nL4 represents an index of refraction of the fourth lens element; nL5 represents an index of refraction of the fifth lens element.
5. The highly correlated relay system of claim 4 , wherein the assembly satisfies three or more of the conditions.
6. The highly correlated relay system of claim 4 , wherein light from the blue region of the spectrum through to the near infrared region of the spectrum follows a same optical path.