The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Apr. 17, 1990
Filed:
Sep. 09, 1988
Trent A Poole, South Amherst, MA (US);
Norman C Ford, Amherst, MA (US);
Barton E Dahneke, Palmyra, NY (US);
Amherst Process Instruments, Inc., Amherst, MA (US);
Abstract
Apparatus, intended primarily for use in an aerodynamic particle sizing system, for generating a pair of closely-spaced light beams, each having a thin, elongated cross-sectional shape. Particle sizes are determined by directing a particle stream through the light beams and measuring the times of flight of particles between the two light beams. The apparatus for generating the light beams includes a laser source and beam forming optics. In one embodiment, a first light beam is formed at the particle stream by a cylindrical lens. After passing through the particle stream, the first light beam is reflected and focused to form a second light beam at the particle stream that is displaced from the first light beam. The first light beam can be reflected and focused by a concave cylindrical mirror or, alternatively, by a flat mirror and a convex cylindrical lens. In another embodiment, the incident light beam from the laser source is passed through a diffraction grating which provides a zero order lobe and a first order lobe. The zero order lobe and the first order lobe are focused at a particle stream by a cylindrical lens to form the first and second beams.