Patent ID: 7483141
Filing Date: 2009-01-27
Classification: G01N

Abstract:
1. A readhead adapted for use in a monitoring system adapted to receive a sample on a sample aperture and determine a parameter valve based on analyzing the sample, the readhead comprising: a first LED having a first center-wavelength associated therewith and being adapted to emit a first path of light; a beam splitter positioned in the first path of light; a second LED positioned relative to the first LED and the beam splitter and having a second center-wavelength associated therewith and being adapted to emit a second path of light intersecting the beam splitter, wherein the first and second paths of light interact with the beam splitter forming a beam of illumination comprising light from the first LED and the second LED; a face defining an exit aperture through which the beam passes, wherein the sample aperture is spaced from the face and positioned to be illuminated by the beam such that when the sample is located on the sample aperture, the sample will reflect at least a portion of the beam; a detector comprising an active area and a detection aperture positioned to receive at least a portion of diffuse light resulting from the reflected beam; and a light-scattering section positioned upstream of the detector active area, the light-scattering section including a plurality of steps defining one or more angles greater than 90 degrees and the section being positioned such that the plurality of steps are angled to reduce stray internal light on the detector active area.