Patent ID: 6759793
Filing Date: 2004-07-06
Classification: F21V,H01J

Abstract:
Lamp unit for a projector, comprising:a high pressure mercury lamp of the short arc type with a wall load of at least 1 W/mm2 which is filled with at least 0.15 mg/mm3 mercury; a concave reflector which surrounds said mercury lamp and has a front opening; and a front cover which covers the front opening of this concave reflector; a cooling means having a controllable cooling intensity for cooling at least one of the concave reflector and the mercury lamp; and a control means for changing the power of the mercury lamp, wherein the cooling means and the control means are constructed for producing a value of WÃ—G/V in a range of 13 being an inside volume of the concave reflector, W (in watts) being a rated luminous output of the mercury lamp, and G being the wall load watts/mm2.