Apochromatic rod lens relay system with reduced spherochromatism and an endoscope with improved relay system

Inventors

Duckett, III, George E.

Assignees

Karl Storz Imaging Inc

Abstract

An image relay system is presented that includes an opposing pair of rod lens assemblies positioned symmetrically with respect to a central airspace. The rod lens assemblies include a meniscus lens positioned immediately adjacent to a central airspace and with the convex surface facing the airspace, a first lens having positive optical power with a convex face positioned adjacent to the inner face of the meniscus lens, a rod lens adjacent to the first lens having positive power, and a second lens having positive optical power positioned adjacent to the rod lens, the relay system designed so that light across a broad spectrum come to a common focus, as well as correcting for spherical aberration across the broad spectrum. An endoscope employing this relay system is also presented.

Core Innovation

The invention provides an apochromatic, reduced-spherochromatism rod-lens relay endoscope that performs broad-spectrum imaging over a continuous spectrum from a minimum wavelength of at least 400 nm through a maximum wavelength of at least 700 nm. The relay system uses opposing symmetric rod lens assemblies positioned symmetrically with respect to a central airspace, and each rod lens assembly includes a meniscus lens immediately adjacent to the central airspace with the convex surface facing the airspace and an inner concave face opposite thereto, followed by a first lens having positive optical power and a rod lens with positive optical power.

Chromatic aberration correction is achieved by manipulating light across the continuous spectrum so that the light comes to a common focus in a common image plane, and spherical aberration is corrected across the continuous spectrum. The corrective structure includes positive-power lenses together comprising the meniscus lens, the first lens, the rod lens, and a second lens having positive optical power with an inner face adjacent to the second face of the rod lens and an outer convex face.

The relay-system architecture enables small f-numbers, including a working f-number less than or equal to 6, and is described as potentially simplified manufacture, including fewer elements per rod assembly and cemented elements. The endoscope includes an objective lens and a proximal lens group to focus the light relayed by the relay system onto the common image plane, and the relay can support fluorescence imaging combined with visible imaging using appropriate sensors and filters, including configurations where the relay reduces the need for complex camera-head corrections.

Claims Coverage

Two independent claims are identified: one directed to a relay system for an endoscope, and one directed to an endoscope including the relay system. Across these independent claims, the core coverage contains three inventive feature clusters: an opposing symmetric corrective rod lens relay architecture around a central airspace with a specific meniscus and positive-power lens arrangement, chromatic and spherical aberration correction across a continuous spectrum to a common focus in a common image plane, and an endoscope architecture with an objective lens and a proximal lens group focusing relayed light onto the common image plane.

The independent claim coverage is centered on a corrective relay system using opposing symmetric rod lens assemblies around a central airspace with a meniscus lens and positive-power lenses, configured to manipulate light across a continuous spectrum to a common focus in a common image plane while correcting chromatic aberration and spherical aberration, and on an endoscope architecture that uses an objective lens and a proximal lens group to focus relayed light onto the common image plane.

Stated Advantages

Documented Applications