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. 15, 2003
Filed:
Feb. 16, 2000
Matsushita Electric Works Research and Development Labs Inc., Woburn, MA (US);
Abstract
An electrodeless fluorescent lamp employs a glass envelope made from a single linear tube or bulb and a reentry cavity disposed on the envelope axis and sealed to the envelope. The envelope is filled with inert gas and mercury vapor. Phosphor and protective coatings are disposed on the inner surfaces of the envelope and the cavity. An induction coil of A few turns made from silver coated copper wire is wrapped around the envelope in its axial direction. The inductively-coupled axially uniform plasma is generated inside the envelope. The discharge electric field and current form a closed-loop path inside the envelope along its walls. The introduction of the reentry cavity decreases the lamp wall loading without loosing lamp power efficiency and efficacy. The lamp is operated at frequencies from 50 kHz to 200 MHz and RF power from 5 W to 2000 W without the use of ferrite inside of the reentry cavity.