16 results about "Relay lens" patented technology

In optics, a relay lens is a lens or lens group that inverts an image and extends the optical tube. Relay lenses are found in refracting telescopes, endoscopes and periscopes for the purpose of extending the length of the system, and before eyepieces for the purpose of inverting an image. They may be made of one or more conventional lenses or achromatic doublets, or a long cylindrical gradient-index of refraction lens (a GRIN lens).