Becton Dickinson and Company Limited

Fmc Corporation

William J Treytl

Robert A Hoffman

Gerry B Andeen

Arthur J Slemmons

A fluorescence particle analyzer includes a flow tube through which particles marked with different fluorochromes pass from a first location to a second location. Emissions from the first and second locations are respectively imaged at respective first and second filter elements so that emissions that reach a photodetector from said first location are primarily filtered by the first filter element, while emission that reach the same photodetector from the second location are primarily filtered by the second filter element. The first filter element is selected to preferentially transmit emissions from a first fluorochrome at the expense of emissions from a second fluorochrome, while the second filter element is selected to preferentially transmit emissions from the second fluorochrome at the expense of emissions from the first fluorochrome. The first location is illuminated by a laser that preferentially excites the first fluorochrome at the expense of the second fluorochrome, while the second location is illuminated by a laser that preferentially excites the second fluorochrome at the expense of the first fluorochrome. The photodetector output includes a first pulse that corresponds predominately to the quantity of the first fluorochrome in the particle; subsequently, a second pulse appears corresponding predominantly to the quantity of the second fluorochrome in the particle. The use of the two filters minimizes cross talk between the fluorochrome emissions in the photodetector output pulses.

Particle analyzer with spatially split wavelength filter

A heliostat apparatus includes a frame which is rotatable about an axis which is parallel to the aperture plane of an elongate receiver. A plurality of flat flexible mirror elements are mounted to the frame between several parallel, uniformly spaced resilient beams which are pivotally connected at their ends to the frame. Channels are mounted to the sides of the beams for supporting the edges of the mirror elements. Each of the beams has a longitudinally varying configuration designed to bow into predetermined, generally circular curvatures of varying radii when the center of the beam is deflected relative to the pivotally connected ends of the beams. All of the parallel resilient beams are simultaneously deflected by a cam shaft assembly extending through openings in the centers of the beams, whereby the mirror elements together form an upwardly concave, cylindrical reflecting surface. The heliostat is rotated about its axis to track the apparent diurnal movement of the sun, while the reflecting surface is substantially simultaneously bowed into a cylindrical trough having a radius adapted to focus incident light at the plane of the receiver aperture.

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San Jose, CA, United States of America

William J Treytl