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:
Jun. 27, 2000
Filed:
May. 22, 1998
Oleg A Popov, Needham, MA (US);
Pradeep K Nandam, Chelmsford, MA (US);
Edward K Shapiro, Lexington, MA (US);
Jakob Maya, Brookline, MA (US);
Matsushita Electric Works R & D Laboratories Inc., Woburn, MA (US);
Abstract
An electrodeless fluorescent lamp and fixture which operates at the frequency range of 50-1000 KHz and power from 20 to 200 W is disclosed. The lamp includes a bulbous envelope (1) filled with rare gas and metal vapor and a reentrant cavity (5). The inner walls of the envelope are coated with phosphor (2) and a protective coating (3). An induction coil (9), made from multiple strands of wire having very low resistance at frequencies below 1000 KHz, together with a ferrite core (10), having high permeability and low power losses, generates an inductively-coupled plasma in the envelope volume. The plasma generates visible and UV radiation that is converted into visible light by the phosphor coated on the envelope walls. A metallic cylinder (13), placed inside the ferrite core (10), removes the heat generated by the plasma from the coil and ferrite core and redirects the heat to the lamp base and thence to the lamp fixture. The power efficiency of the lamp operated at frequencies 200-300 KHz and its efficacy are the same as those in electrodeless RF lamps operated at frequencies of 2.65 MHz and at 13.56 MHz.