Patent ID: 6894779
Filing Date: 2005-05-17
Classification: G01N

Abstract:
1. A back-scatter detector for detecting light scattered backwardly from an individual particle or blood cell irradiated by a light beam at a particle interrogation zone within an optical flow cell of a blood cell analyzer, said back-scatter detector comprising: (a) a photodetector; (b) a plurality of optical fibers, each having a light-collection end, an opposing light-discharge end, and an intervening light-transport region for transmitting, by multiple internal reflections, light collected by said light-collecting end, to said light-discharge end said light-discharge end being positioned proximate a light-sensitive face of said photodetector; and (c) a fiber optic holder comprising a housing having a centrally located opening therein for passing a light beam used to irradiate particles at said particle interrogation zone, said fiber optic holder operating (i) to position the respective light-collecting ends of said optical fibers at a desired position to collect said back-scattered light, and (ii) to support linear portions of said optical fibers in the vicinity of their respectiv light-collecting ends so that the loagitudinal axes of said supported linear portions converge at or near the anticipated location of said particle-interogation zone, said housing of said optical fiber holder comprising a tubular portion adapted to engage a lens housing of a lens system adapted to focus said light beam at said interrogation zone and thereby provide support for said optical fiber holder between said lens system and said particle-interrogation zone.