Abstract: A high pressure discharge lamp including discharge tube having at least two electrodes at opposite ends thereof, an outer bulb housing the discharge tube, a circuit for starting the discharge tube and a glow starter which is covered with a heat shield member and disposed between the discharge tube and the outer bulb.

Abstract: A high-pressure metal halide arc discharge lamp having an arc tube with a pair of main electrodes disposed within the tube at opposite ends and a starting electrode located adjacent one of the main electrodes. A tubular sleeve of insulating material, such as quartz, is disposed about the starting electrode, which is recessed within the sleeve but exposed through the open end thereof to the interior atmosphere of the arc tube. Since the starting electrode does not project beyond the open end of the sleeve, conduction between that electrode and the adjacent main electrode is minimized or prevented during normal lamp operation, thereby minimizing or preventing electrolysis.