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:
Sep. 18, 2007
Filed:
Nov. 15, 2005
Jakke Mäkelä, Turku, FI;
Timo Kolehmainen, Oulu, FI;
Timo Tokkonen, Oulu, FI;
Kai Ojala, Oulu, FI;
Nokia Corporation, Espoo, FI;
Abstract
An apparatus for quantifying irradiance has a first sensor having an output for providing a reference signal of irradiance within a first band, such as the visible light band. A filter and a second sensor are in optical series so that irradiance sensed at the second sensor is filtered. The second sensor outputs a filtered signal of irradiance within the first band. The filter particularly filters irradiance in the first band as a function of irradiance in the second band, such as the UV light band. In an exemplary embodiment, the filter is made from a material that darkens with increasing UV irradiance. A processor has inputs coupled to the outputs of the first and second sensors for determining irradiance in the second band from the reference signal and the filtered signal. Mathematical formulations for the processor are provided, as are methods and a computer program embodied on a medium. A single sensor embodiment is also described.