Patent ID: 6510007
Filing Date: 2003-01-21
Classification: G01N,G02B

Abstract:
A lens system for flow cytometry, comprising:a plano-convex lens of a single material of less than 1.55 refractive index with a planar surface thereof defining an object side of the system and with a convex surface having a radius of curvature in a range from 3.5 to 5.5 mm; a pair of meniscus lenses having concave surfaces thereof facing the object side of the system, the surfaces of the second meniscus lens being less sharply curved than corresponding surfaces of the first meniscus lens, the convex surface of the first meniscus lens being less sharply curved than the convex surface of the plano-convex lens; and a pair of doublet lenses; all of the refractive surfaces and distances being optimized for a working distance of at least 1.75 mm, a field of view of at least 400 &mgr;m diameter, an RMS spot size in image space of less than 100 &mgr;m, and a numerical aperture of at least 1.17 for a lens magnification in excess of 10.