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. 07, 1981
Filed:
Feb. 12, 1979
Gustaaf A Wesselink, Eindhoven, NL;
Hendrik Roelofs, Eindhoven, NL;
Cornelis H Van Bommel, Eindhoven, NL;
U.S. Philips Corporation, New York, NY (US);
Abstract
Low-pressure mercury vapor discharge lamps of the fluorescent type are known which comprise two nesting glass members so grooved as to provide between their nesting surfaces a circuitous ('folded') discharge path between two electrodes, the length of the discharge path being considerably greater than the physical distance between the electrodes. The whole surface of each glass member is coated with luminescent material with the result that, when the lamp is in use, the portions of the members not surrounding the discharge appear dark due to their poor light transmissibility. According to the invention, these portions of the two members are not coated with luminescent material and thus act as windows for light generated in the luminescent layers facing the lamp axis. Preferably, a fluted reflector is provided inside the lamp.