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:
Nov. 16, 1993
Filed:
Oct. 16, 1991
James L Blesener, White Bear Lake, MN (US);
Thomas G Halvorsen, Blaine, MN (US);
TSI Incorporated, St. Paul, MN (US);
Abstract
A vacuum particle detector includes a cavity providing a passage for fluid flow, a laser diode and beam shaping optics to form a substantially rectangular beam spanning the chamber. Light sensing optics, including a pair of biconvex lenses, receive light scattered when the particles suspended in the fluid intersect the beam. At least some of the scattered light is transmitted through the lenses to a photodetector. The photodetector width is selected in concert with the focal lengths of the biconvex lenses, to provide a viewing depth of field commensurate with the complete span of the beam across the chamber, whereby the photodetector responds to particles that intersect the beam over the entire span. A cone and a surrounding sleeve, both concentric about an axis of the beam, absorb the laser energy beam to provide an effective beam stop.