Optical extinction photoanalysis apparatus for small particles

Claim 1

Apparatus for optical measurement of at least one characteristic of each particle of a group of small particles such as blood cells while the particles are suspended in a liquid, comprising a source of light operable to produce a narrow beam having substantially parallel beam elements and having well defined outer beam margins, a housing comprised of a material which transmits light from said source and defining an optical chamber, means for moving the particle suspending liquid through said housing in a thin narrow stream substantially centered in said chamber to convey the particles in sequence through the stream one by one, means for directing the narrow beam of light into one side of said housing to intersect with the thin stream of particles, said light directing means being operable to cause the beam to converge to the intersection with the stream of particles at a small angle of convergence between the outer beam margins to thereby concentrate the energy of the beam upon the particle stream, a photoresponsive pick-up element positioned outside of said housing in alignment with the light beam on the side of said housing opposite to said light source to directly receive the unscattered illumination from the light beam to thereby detect the degree of extinction of light by each particle, and masking means positioned in front of said photoresponsive pick-up element to intercept illumination scattered away from the direct path of the light beam by the particles in the particle stream to thereby mask said photoresponsive pick-up element from scattered illumination.

Claim 4

An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid, comprising a source of light operable to produce a narrow beam having substantially parallel beam elements and having well defined outer beam margins, a cylindrical tube member defining an optical chamber, said tube member being comprised of a material which transmits light from said source, means for directing the narrow beam of light into one side of said tube member in a beam substantially converging at the center of said optical chamber when viewed in a direction perpendicular to the axis of said tube member defining said chamber, means for moving the particle suspending liquid through said tube member in a thiN narrow stream substantially centered in said chamber to cause the particles therein to pass in sequence through said light beam one by one, a photoresponsive pick-up element positioned and arranged in direct alignment with the light beam on the side of said tube member opposite to said light source to directly receive the unscattered illumination from the light beam to thereby detect the degree of extinction of light by each particle, and masking means positioned in front of said photoresponsive pick-up element to intercept illumination scattered away from the direct path of the light beam by the particles in the particle stream to thereby mask said photoresponsive pick-up element from scattered illumination.

Claim 5

An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid, comprising a source of light operable to produce a narrow beam having substantially parallel beam elements and having well defined outer beam margins, a cylindrical tube member defining an optical chamber, said tube member being comprised of a material which transmits light from said source, means for directing the narrow beam of light into one side of said tube member in a beam substantially converging at the center of said optical chamber when viewed in a direction perpendicular to the axis of said tube member defining said chamber, means for moving the particle suspending liquid through said tube member in a thiN narrow stream substantially centered in said chamber to cause the particles therein to pass in sequence through said light beam one by one, a photoresponsive pick-up element positioned and arranged in direct alignment with the light beam on the side of said tube member opposite to said light source to directly receive the unscattered illumination from the light beam to thereby detect the degree of extinction of light by each particle, and masking means positioned in front of said photoresponsive pick-up element to intercept illumination scattered away from the direct path of the light beam by the particles in the particle stream to thereby mask said photoresponsive pick-up element from scattered illumination.

Claim 8

An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid comprising a housing defining an optical chamber, a source of light operable to produce a narrow beam having substantially parallel beam elements and having well defined outer beam margins, said housing member being comprised of a material which transmits light from said source, means for moving the particle suspending liquid through said housing member in a thin narrow stream substantially centered in said chamber to thereby convey the particles in sequence through the light beam one by one, means for directing the narrow beam of light from said light source into one side of said housing to intersect with the thin stream carrying the particles therein, said means for directing said light being operable in cooperation with said side of said housing to converge said light beam at a small angle of convergence between the outer beam margins into a substantially elliptical shape in a plane transverse to the light beam and converging at the point of intersection with the position of the thin stream of particles to thereby concentrate the energy of the beam upon the particle stream, the major axis of the elliptical shape of said beam being substantially perpendicular to the direction of the stream of particles and the dimension of said beam at said major axis being substantially greater than the transverse dimension of said particle stream, a photoresponsive pick-up element positioned and arranged in direct alignment with the light beam on the side of said housing opposite to said light source to directly receive the unscattered illumination from the light beam to thereby detect the degree of extinction of light by the particles being measured, and masking means positioned in front of said photoresponsive pick-up element to intercept illumination scattered away from the direct path of the light beam by the particles in the particle stream to thereby mask said photoresponsive pick-up element from scattered illumination.

Claim 9

An apparatus for rapid optical measurement of the characteristics of small particles such as blood cells while the particles are suspended in a liquid comprising a housing defining an optical chamber, a source of light operable to produce a narrow beam having substantially parallel beam elements and having well defined outer beam margins, said housing member being comprised of a material which transmits light from said source, means for moving the particle suspending liquid through said housing member in a thin narrow stream substantially centered in said chamber to thereby convey the particles in sequence through the light beam one by one, means for directing the narrow beam of light from said light source into one side of said housing to intersect with the thin stream carrying the particles therein, said means for directing said light being operable in cooperation with said side of said housing to converge said light beam at a small angle of convergence between the outer beam margins into a substantially elliptical shape in a plane transverse to the light beam and converging at the point of intersection with the position of the thin stream of particles to thereby concentrate the energy of the beam upon the particle stream, the major axis of the elliptical shape of said beam being substantially perpendicular to the direction of the stream of particles and the dimension of said beam at said major axis being substantially greater than the transverse dimension of said particle stream, a photoresponsive pick-up element positioned and arranged in direct alignment with the light beam on the side of said housing opposite to said light source to directly receive the unscattered illumination from the light beam to thereby detect the degree of extinction of light by the particles being measured, and masking means positioned in front of said photoresponsive pick-up element to intercept illumination scattered away from the direct path of the light beam by the particles in the particle stream to thereby mask said photoresponsive pick-up element from scattered illumination.