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:
Sep. 17, 1991
Filed:
Apr. 09, 1990
John W Shaffer, Danvers, MA (US);
GTE Products Corporation, Danvers, MA (US);
Abstract
A negative glow fluorescent lamp includes a light-transmissive envelope enclosing a fill material which emits ultraviolet radiation upon excitation, a phosphor coating on an inner surface of the envelope, the phosphor coating emitting visible light upon absorption of ultraviolet radiation, a cathode located within the envelope for emitting electrons, first and second cathode leads extending through the envelope, an anode located in the envelope and spaced from the cathode for collecting electrons and first and second diodes coupled between opposite ends of the anode and the first and second cathode leads, respectively. The glow lamp can include one or more insulating discharge barriers which surround the cathode and block electron bombardment of the cathode during positive half cycles of the AC voltage. The discharge barriers are preferably as large in area as is practical and can be coated with an ultraviolet-reflecting material or with a phosphor layer. The glow lamp operates from an AC voltage and requires only two electrical connections. Lumen maintenance is improved because electron bombardment of the cathode is eliminated. A simple, low-cost ballast can be utilized.