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. 27, 2009
Filed:
May. 15, 2003
Brian Powell, Maidenhead, GB;
Brian Powell, Maidenhead, GB;
Kidde IP Holdings Limited, , GB;
Abstract
A smoke detector () has a spherical chamber () including a plurality of holes () for allowing smoke and other particles to enter the chamber. The majority of the internal surface () of the chamber () is covered with a high reflectivity Lambertian surface, that is a material that scatters incident light equally in all directions and at all wavelengths. The remaining portion of the internal surface () is coated with a light absorbing material () such as a matt black coating. A scatter sensor () is directed towards the absorbing coating (), and an integrating detector () is configured to detect radiation directly from the entire Lambertian surface. A first LED () emits blue light into the chamber (), and a second LED () emits infrared light into the chamber. Processing means (and) are provided to analyse the signals from the detectors (), including means for discriminating between signals from the sensors indicative of different frequencies of received radiation. The processing means can distinguish between different smoke types, such as white/grey smoke and black smoke, and can also distinguish between smoke and other particles.