LCD projection lens
AssigneeU.S. Precision Lens Incorporated
InventorJacob Moskovich
Life of this patent
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Abstract
A projection lens for use with a pixelized panel (LCD) is provided. The lens has two positive lens units with an aperture stop between them. The optical powers of each of the units are such that f1 is substantially shorter than f2, where f1 and f2 are the focal lengths of the first lens unit and the second lens unit, respectively, the first lens unit being on the system's long conjugate side and the second lens unit being on the short conjugate side. The ratio of f1 to f2 is preferably less than about 0.75.
Claims16
A projection lens for forming an image of an object, said lens having an aperture stop and consisting in order from its image end to its object end of:
- (a) a first lens unit having a positive optical power and a focal length f1;
- (b) a second lens unit having a positive optical power and a focal length f2;
- wherein the aperture stop is located between the first and second lens units, f1 is shorter than f2, and the lens has a back focal length approximately equal to the lens' focal length.
Dependencies are inferred from the claim text.