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. 23, 2006
Filed:
Nov. 24, 2004
Huiling Zhu, Lexington, MA (US);
Jakob Maya, Brookline, MA (US);
Huiling Zhu, Lexington, MA (US);
Jakob Maya, Brookline, MA (US);
Matsushita Electric Works Ltd., Osaka, JP;
Abstract
A lighting system includes a high intensity discharge metal halide lamp having an arc discharge chamber with electrodes at each end and containing a fill of mercury, rare gas and metal halides, and a ballast circuit configured to supply pulsed electrical power to the lamp. The ballast circuit includes a controller configured to adjust the pulsed lamp power between a first relatively high power level at a relatively high duty cycle and a second relatively low power level at a relatively low duty cycle. The controller may be configured to adjust the pulsed lamp power between 90% duty cycle at rated lamp power and 10% duty cycle at 30% of the rated lamp power. The duty cycle of the pulsed lamp power may be controlled to maintain a substantially constant correlated color temperature (CCT) as the power level is adjusted.