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:
Apr. 26, 2016
Filed:
Mar. 23, 2008
Rakesh Roshan, Oxford, GB;
Benjamin James Hadwen, Oxford, GB;
David James Montgomery, Oxford, GB;
Jonathan Heffernan, Oxford, GB;
Rakesh Roshan, Oxford, GB;
Benjamin James Hadwen, Oxford, GB;
David James Montgomery, Oxford, GB;
Jonathan Heffernan, Oxford, GB;
Sharp Kabushiki Kaisha, Osaka, JP;
Abstract
An illumination system comprises at least two light sources () having different emission spectra to one another; a detection circuit () for sensing a light intensity using at least one of the light sources as a photosensor; and driving means () for driving the light source in dependence on the sensed spectral distribution of light. The emission spectrum of a light source with the smallest bandgap overlaps the emission spectrum of a light source with the second-smallest bandgap. The illumination system is possible to measure the intensity of light emitted by the light source with the smallest bandgap by putting the light source with the second-smallest bandgap in detection mode. The illumination system may also sense the spectral distribution of ambient light, to allow the output from the illumination system to be adjusted in dependence on the ambient light.