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:
Jan. 04, 2000
Filed:
Apr. 29, 1998
Nittan Company, Limited, Tokyo, JP;
Abstract
A smoke sensor includes a light receiving unit for temporally alternately receiving scattered light of two different wavelengths .lambda..sub.1 and .lambda..sub.2 ; a calculating unit for performing a calculation required for smoke detection, on a scattered light output y of the wavelength .lambda..sub.1 and a scattered light output g of the wavelength .lambda..sub.2 from the light receiving unit; and a smoke detection processing unit for performing a smoke detection process on the basis of a calculation result output from the calculating unit. The calculating unit estimates an output value of one of the scattered light output y of the wavelength .lambda..sub.1 and the scattered light output g of the wavelength .lambda..sub.2 at a sample timing of the other output, and obtains a ratio of the estimated output value of the one scattered light at the sample timing of the other output to an output value of the other scattered light, as a two-wavelength ratio.