Abstract: The present invention is directed to a lens assembly which includes a lens element having a front face and a back face and a peripheral edge; a lens cell having an axial bore and a radially inwardly extending lens seat, the lens seat having a radially seating surface for engaging one of the lens faces, the peripheral edge of the lens element being radially spaced from the inner wall of the lens cell; a retainer ring mounted removably, adjustably, rigidly in the seating surface substantially equal to the thickness of the element, the retaining ring having a plurality of radially inwardly directed fingers which are disposed closely adjacent the other of the lens faces; and an adhesive disposed axially between the retainer ring fingers and the other lens face for tying the lens to the retainer after alignment of the lens whereby the lens and the retainer ring are removable from the lens cell as a single integral unit.

Abstract: This invention is directed to a mask ring assembly for X-ray lithography which is particularly adapted, among other possible uses, for use in replicating integrated circuit patterns, said assembly including a mask ring, a plurality of kinematic mounts for removably mounting the mask ring on an alignment cartridge, each of the kinematic mounts including a funnel-like shaped seat member and a mating ball-like shaped member, one of said members being on the mask ring and the other of the members being mounted on the alignment cartridge.