Reflection rejection spherical optical train composed of tipped lens elements

摘要

A reflection rejecting spherical optical train is disclosed. At least two optical elements each having cylindrical components are disposed along an optical axis. The elements are each crossed one with respect to another so that the total and combined optical output comprises an overall spherical lens. Each of the lens elements having a cylindrical component is tilted with respect to planes normal to the optic axis. Light passing along the optical axis which is reflected at the defined optical interfaces is rejected by the reflection at angles which do not include a return along the optic axis; reflection rejection occurs. Preference is given to a lens train of three or more lens elements having cylindrical components, with the near point of each tilted lens element being located at equal angular intervals about the optic axis. A preferred embodiment is illustrated utilizing three tipped spherical lens elements-typically positive-which with each of these elements having its near point to one end of the lens train spaced at 120 DEG angular intervals about the optic axis.