PROJECTION LENS Russian patent published in 1997 - IPC

FIELD: optical instrumentation engineering, design of projection instrumentation devices and other optical systems. SUBSTANCE: projection lens includes two groups of lenses-first group is composed of five lenses of which first, third and fourth ones are cemented ones second group includes cemented lens having negative focal power. First and second lenses have positive focal power. First and second lenses make up first component, third and fourth lenses - second component. First and second components form projection system with magnifying power close to 1^x. Second and fifth lenses are made cemented. Third and fourth lenses have positive focal power and fifth one - negative focal power. EFFECT: improved operational stability. 9 dwg