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:
May. 10, 2016
Filed:
Jul. 01, 2014
Ming LI, Acton, MA (US);
Qi Dai, Peabody, MA (US);
Keng Chen, Sudbury, MA (US);
OSRAM SYLVANIA INC., Wilmington, MA (US);
Abstract
Techniques are disclosed for maintaining consistent lumen output of a lighting assembly over time. By maintaining a consistent lumen output, it is possible to maintain acceptable color stability where color mixing of multiple outputs is used. The lighting assembly may be any lighting configuration that might suffer from lumen depreciation and/or color drift over time, and may include any type(s) of light source(s) that may be monitored and driven accordingly. The lighting assembly, in addition to light source(s), includes a photo detector and a directed light source, such as a laser. The directed light source provides a golden sample for use in calibrating the photo detector, which in turn monitors lumen output of the light source(s). Drive signals are adjusted to account for lumen depreciation of the monitored light source(s).