Plano convex fluid carrier for scattering correction
AssigneePointSource Technologies, LLC
InventorDavid A. Drake
Life of this patent
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Abstract
A system for identifying microorganisms and other microscopic particles in a fluid, includes a laser that directs a laser beam (14) through a detect zone (20) and a plurality of photodetectors (30) that detect light scattered in different directions from a particle at the detect zone. The system includes a glass carrier (110) that confines fluid to movement along a narrow passage (116) in the carrier. The front surface (130) of the passage is flat, to facilitate prediction of the scatter light paths, and to enable the passage to have a small cross-sectional area.
Claims9
A system for detecting and identifying microscopic particles, comprising:
- a carrier formed of a solid transparent material, said carrier having a passage through which fluid with particles can pass, said passage having a vertical axis, said carrier defining a horizontal centerplane that is normal to said axis, and said carrier having an outer surface with upper and lower surface portions that are inclined respectively upwardly and toward said axis, and downwardly and toward said axis;
- a light source that generates a beam of light that travels forwardly along said horizontal centerplane and though said axis, and that defines a detect zone
- where said beam passes through said axis;
- a plurality of photodetectors that lies outside said carrier outer surface and that detect light scattered in different directions from a particle lying in said detect zone;
- said passage having a front wall which is flat.
A system for detecting and identifying microscopic particles, comprising:
- a carrier formed of a solid transparent material, said carrier having a passage through which fluid with particles can pass, said passage having a vertical axis, said carrier defining a horizontal centerplane that is normal to said axis, and said carrier having an outer surface with upper and lower surface portions that are inclined respectively upwardly and toward said axis, and downwardly and toward said axis;
- a light source that generates a beam of light that travels forwardly along said horizontal centerplane and though said axis, and that defines a detect zone where said beam passes through said axis;
- a plurality of photodetectors that lies outside said carrier outer surface and that detect light scattered in different directions from a particle lying in said detect zone;
- said carrier comprising a plurality of separate pieces of transparent material that is fastened together.
Apparatus for use in a system for detecting and/or identifying microscopic particles in a fluid, which includes a source that generates a light beam that travels along a forward longitudinal direction through a detect zone, and a plurality of photodetectors that detect light scattered in different directions from said detect zone, comprising:
- a carrier constructed of a solid transparent material, said carrier having walls forming a passage extending along a passage axis for carrying the fluid that contains particles, and said carrier walls forming an outside surface, so at least said photodetectors can lie outside said outside surface and detect light from a detect zone that lies along the light beam and in the passage;
- said passage has a front surface which is planar;
- there is a predetermined longitudinal distance between a center of said detect zone and said passage front surface, and said passage has a width in a lateral direction which is at least six times said longitudinal distance, whereby to enable light scattered from said center of said detect zone at an angle of about 70° to said beam path to pass through said planar front surface.
Apparatus for use in a system for detecting and/or identifying microscopic particles in a fluid, which includes a source that generates a light beam that travels along a forward longitudinal direction through a detect zone, and a plurality of photodetectors that detect light scattered in different directions from said detect zone, comprising:
- a carrier constructed of a solid transparent material, said carrier having walls forming a passage extending along a passage axis for carrying the fluid that contains particles, and said carrier walls forming an outside surface, so at least said photodetectors can lie outside said outside surface and detect light from a detect zone that lies along the light beam and in the passage;
- said passage has a front surface which is planar;
- said passage has curved laterally spaced side walls that are each concavely curved and that have front ends that are substantially tangential to said front wall.
Apparatus for use in a system for detecting and/or identifying microscopic particles in a fluid, which includes a source that generates a light beam that travels along a forward longitudinal direction through a detect zone, and a plurality of photodetectors that detect light scattered in different directions from said detect zone, comprising:
- a carrier constructed of a solid transparent material, said carrier having walls forming a passage extending along a passage axis for carrying the fluid that contains particles, and said carrier walls forming an outside surface, so at least said photodetectors can lie outside said outside surface and detect light from a detect zone that lies along the light beam and in the passage;
- said passage has a front surface which is planar;
- said light beam has a predetermined width in a lateral horizontal direction that is perpendicular to said beam path and to said passage axis, and said passage has a length along said longitudinal direction, which is no more than 4 times said beam width, and said passage has a width in a lateral direction that is perpendicular to said beam path which is no more than four times said width, whereby to enable a considerable portion of the fluid to pass through the detect zone.
Dependencies are inferred from the claim text.