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:
Mar. 15, 1994
Filed:
Feb. 12, 1993
John S Batchelder, Somers, NY (US);
Donald M DeCain, New York, NY (US);
Philip C Hobbs, Briarcliff Manor, NY (US);
International Business Machines Corporation, Armonk, NY (US);
Abstract
A particle detector that determines the presence of particles in an enclosed volume includes a laser that directs an optical beam to a beam splitter that produces first and second beams. An optical system directs the first beam into the enclosed volume. A detector is positioned adjacent the volume in order to receive back scattered optical energy arising from a particle in the volume encountering the first beam. The back scattered optical energy and the second beam are optically combined so as to overlap in a region and in the overlap region the back scattered optical energy and second beam are in the same state of focus, of the same polarization and are substantially parallel. A detector located at the overlap region produces an electrical signal indicative of the intensity of the back scattered light. A signal processor analyzes the electrical signal to determine the presence of the particle.