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:
Jun. 29, 2004
Filed:
Mar. 26, 2002
Shunsaku Nakauchi, Mitaka, JP;
Masanori Hirasawa, Tokorozawa, JP;
Kokusai Gijutsu Kaihatsu Kabushiki Kaisha, Tokyo, JP;
Abstract
A flame sensor comprises a filter which blocks light in an infrared ray region, a filter which blocks stray light, a narrow band filter which passes only light of a band corresponding to a line spectrum of carbonic acid gas resonance radiation generated by a flame, and a broad band filter which passes light of a band which is broader than the band corresponding to the line spectrum, and a plurality of light reception elements which convert lights passing through the narrow and broad band filters to electric signals, the flame sensor judging flame when a difference between intensities of the electric signals is equal to or more than a predetermined value and a ratio between the intensities of the electric signals is within a predetermined range, by assuming that transmission band widths of the narrow and broad band filters are equal, is provided.