Abstract: The invention relates to a metal halide lamp for a vehicle headlamp comprising a cylindrically-shaped discharge vessel (23) having a ceramic wall which encloses a discharge space comprising Xe and ionizable filling, and a cylindrically-shaped outer bulb (21) surrounding the discharge vessel (23). According to the invention a portion (25, 26) of the surface of the outer bulb (21) facing away from the discharge vessel (23) is shaped as a negative lens. Preferably, the portion (25, 26) encompasses a segment of the outer bulb (21) with a segment angle ? in the range between 30???60°. Preferably, the portion (25) forming the negative lens is shaped as a flat surface.

Abstract: The invention relates to an illumination system(100), a high-pressure discharge lamp (90) and an image projection system. The illumination system comprises a high-pressure discharge lamp and a back reflector (30) reflecting the light emitted by the high-pressure discharge lamp towards a light exit window (50). The back reflector comprises an optical axis (55). The high-pressure discharge lamp comprises a discharge vessel (90) comprising two electrodes (98, 99) between which, during operation, a discharge arc is produced. The discharge vessel comprises a first part (10) arranged at least partially between the discharge arc and the back reflector, and a second part (20) arranged at least partially between the discharge arc and the light exit window. The second part has a different shape compared to the first part, thereby forming a refractive element in the second part for reducing an angular distribution at the light exit window of the light emitted from the discharge arc and refracted By the second part.

Abstract: The invention relates to a metal halide lamp for a vehicle headlamp comprising a cylindrically-shaped discharge vessel (23) having a ceramic wall which encloses a discharge space comprising Xe and ionizable filling, and a cylindrically-shaped outer bulb (21) surrounding the discharge vessel (23). According to the invention a portion (25, 26) of the surface of the outer bulb (21) facing away from the discharge vessel (23) is shaped as a negative lens. Preferably, the portion (25, 26) encompasses a segment of the outer bulb (21) with a segment angle ? in the range between 30???60°. Preferably, the portion (25) forming the negative lens is shaped as a flat surface.

Abstract: The invention relates to a metal halide lamp which is provided with a discharge vessel having a ceramic wall and enclosing a discharge space. Two electrodes having tips at a mutual distance EA are positioned in the discharge space, which contains besides Xe also an ionizable filling with NaI and CeI3. The discharge vessel has an internal diameter Di at least over the length EA. According to the invention it holds that Di<1.4 mm and also that the relation EA/Di<5 is complied with.