Patent ID: 6646742
Filing Date: 2003-11-11
Classification: G01N

Abstract:
A particle analyzing apparatus for discriminating particulate element(s) in a fluid flow for purposes of analysis, classification, sorting, and presentation, the apparatus comprising:an illumination source to emit an illumination beam along an optical axis of the apparatus, wherein the illumination beam includes an intensity peak and at least one null; a flow cell, positioned along the optical axis, having a flow path extending through the flow cell, the flow path having a portion of a surface to receive the illumination beam emitted from the illumination source, wherein the intensity peak of the illumination beam is substantially centered on the portion of the surface and the null of the illumination beam is positioned at an edge of the portion of the surface; a sample supply to introduce a fluid to the flow path of the flow cell; and a light sensor, positioned along the optical axis, to receive at least light passed from the flow cell in response to an interaction with an illumination beam emitted by the illumination source and a fluid supplied to the flow passage of the flow cell, wherein the flow cell is oriented to prevent formation of back light reflection parallel to the optical axis in response to an emission of an illumination beam from the illumination source.