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. 01, 2008
Filed:
Dec. 10, 2003
Ashfaqul I. Chowdhury, Mayfield Heights, OH (US);
Rajasingh Israel, Westlake, OH (US);
Gary R. Allen, Chesterland, OH (US);
Ashfaqul I. Chowdhury, Mayfield Heights, OH (US);
Rajasingh Israel, Westlake, OH (US);
Gary R. Allen, Chesterland, OH (US);
General Electric Company, Schenectady, NY (US);
Abstract
A metal halide lamp () includes a light-transmissive envelope () which encloses a metal halide pool () for generating a discharge when spaced apart electrodes () within the envelope are supplied with an electric current. A multi-layer coating () is deposited on a surface () of the envelope. The coating includes several layers of at least two materials of different refractive index, which, in combination, reflect radiation in the UV region of the electromagnetic spectrum. Rather than optimizing the coating for a normal (i.e., 0°) angle of incidence on the coating, the multi-layer coating is optimized at an angle which is selected to be within 10° of the mean angle (α) of incidence of the UV radiation on the arctube surface, thereby increasing the amount of UV radiation which is returned to the metal halide pool. The coating is preferably optimized for high reflectivity in the UV-region of the spectrum and high transmission in the visible region of the spectrum to maximize useful light output while reflecting UV light back to the metal halide pool for improved heating of the pool.