MICROOBJECTIVE WITH INCREASED OPERATING DISTANCE Russian patent published in 1997 - IPC

FIELD: testing of microelectronic articles. SUBSTANCE: microobjective has four components. First component includes ″p″ frontal single lenses the number of which is selected depending on objective magnification (P = 0,034V_ob),. Second component is represented by two doubly glued lenses facing each other with their positive lenses made of material with dispersion factor exceeding 90. The third is single positive component, and fourth component is doubly glued component consisting of concave-convex and biconcave lenses. Dispersion factor of biconcave lens is 1.5 times as high as that of concave-convex lens. EFFECT: more efficient design. 7 dwg