Abstract: To increase operating temperature, and hence vapor pressure, the arc tube ose to the arc, typically an inner arc tube, is at least partially frosted. The outer bulb which surrounds the inner arc tube may also be frosted. The lamps have low color temperature and good color rendering index at high luminous output. The fill preferably includes metal halides of rare earth metals, and/or mercury. The outer bulb is preferably in the form of a reflector bulb.

Abstract: The invention relates to a starting and operating device, including an intance in the ignition circuit, for a high pressure discharge lamp, especially for a high pressure mercury vapor discharge lamp with metal halide additive, having at least one starting electrode positioned near one of the main electrodes within the discharge vessel. The starting electrode and the main electrode remote from the starting electrode are bridged by an electric circuit externally of the discharge vessel which comprises a current-interrupting and/or current-limiting electrical component. This arrangement of an auxiliary electrode within the discharge vessel of a high pressure discharge lamp brings about a reduction of the supply voltage required for initiation of the discharge which is particularly desirous in the case of high pressure mercury vapor discharge lamps containing metal halides.