Invention Grant
- Patent Title: Optimized ultraviolet reflecting multi-layer coating for energy efficient lamps
- Patent Title (中): 用于节能灯的紫外线反射多层涂层的优化
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Application No.: US10732885Application Date: 2003-12-10
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Publication No.: US07352118B2Publication Date: 2008-04-01
- Inventor: Ashfaqul I. Chowdhury , Rajasingh Israel , Gary R. Allen
- Applicant: Ashfaqul I. Chowdhury , Rajasingh Israel , Gary R. Allen
- Applicant Address: US NY Schenectady
- Assignee: General Electric Company
- Current Assignee: General Electric Company
- Current Assignee Address: US NY Schenectady
- Agency: Fay Sharpe LLP
- Main IPC: H01J61/35
- IPC: H01J61/35 ; H01J5/16

Abstract:
A metal halide lamp (10) includes a light-transmissive envelope (12) which encloses a metal halide pool (30) for generating a discharge when spaced apart electrodes (20, 22) within the envelope are supplied with an electric current. A multi-layer coating (40) is deposited on a surface (42) 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.
Public/Granted literature
- US20050127840A1 Optimized ultraviolet reflecting multi-layer coating for energy efficient lamps Public/Granted day:2005-06-16
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