Patent ID: 7621868

Claim:
An optical system for viewing an object stereoscopically comprising: A) a stereoscopic endoscope for transmitting images of the object along each of two channels wherein the object is located at a working distance from a distal end of said endoscope, B) a stereoscopic viewing system that displays a stereoscopic image in response to incoming images, and C) one of a plurality of convergence couplers intermediate said endoscope and said viewing system for differentially redirecting the light collected from the object to the stereoscopic viewing system whereby each convergence coupler provides an optimal convergence distance for stereoscopic viewing for a different working distance whereby an exchange of said convergence couplers modifies the image convergence to accommodate different working distances, each said convergence coupler including: i) a first optical assembly for transferring a first light ray from an object point received from the first channel along a first input axis to said viewing system along a first output axis, ii) a second optical assembly for transferring a second light ray from the same object point received along a second input axis from the second channel to said viewing system along a second output axis, iii) each of said first and second optical assemblies including first and second contiguous optical elements that redirect the first and second light rays correspondingly, and iv) means for orienting said first and second optical assemblies relative to a reference plane whereby said first and second output axes are complementary and define an angle therebetween that optimizes the image separation at the viewing system for the corresponding working distance.