Low power discharge lamp with high efficacy

Patent metadata

Field	Value
Publication number	US-RE45342-E
Application number	US-200814026505-A
Country	US
Kind code	E1
Filing date	Mar 7, 2008
Priority date	Mar 12, 2007
Publication date	Jan 20, 2015
Grant date	Jan 20, 2015

Abstract

In order to achieve a discharge lamp suited to operate under reduced nominal power of e.g. 20-30 W, a lamp is proposed with two electrodes ( 24 ) arranged at a distance in a discharge vessel ( 20, 120 ) for generating an arc discharge. The discharge vessel ( 20,120 ) has a filling with a substantially free of mercury and comprises a metal halide and a rare gas. The lamp ( 10, 110 ) further comprises an outer bulb ( 18 ) arranged around the discharge vessel at a distance (d 2 ). The outer bulb ( 18 ) is sealed and has a gas filling of a thermal conductivity (λ). The inner diameter (d 1 ) of the discharge vessel is preferably in a range from 2-2.7 mm. The wall thickness (w 1 ) is in a range from 1.4-2 mm. A heat transition coefficient (λ/d 2 ) is calculated as thermal conductivity (λ) at 800° C. of the outer bulb filling divided by the distance (d 2 ). The so-defined heat 10 transition coefficient is below 150 W/(m 2 K).

First claim

The invention claimed is:

1. A high intensity discharge lamp, comprising:
a discharge vessel defining a discharge space being essentially free of mercury and containing at least a metal halide and a rare gas;
two electrodes disposed within the discharge vessel for generating an arc discharge a wall forming the discharge space disposed between the electrodes, the wall having substantially circular cross-section with an inner diameter (d 1 ) and a wall thickness (w 1 ), and
an o…

Assignees

• Koninkl Philips Nv

Inventors

• Haacke Michael
• Stroesser Martin

Classifications

• H01J61/33

  Electricity · mapped topic

• H01J61/34 Primary

  Electricity · mapped topic