High pressure metal vapor discharge lamp.

摘要

A high-pressure metal vapor discharge lamp comprises: an arc tube (12), which is shunted by a series circuit of a thermal switch (14) and a non-linear ceramic capacitor (16), a pyroelectric current bypassing resistor (22) connected in parallel to the non-linear ceramic capacitor (16), and a lamp outer bulb (20) incorporating the arc tube (12), the thermal switch (14), the non-linear ceramic capacitor (14) and the resistor (22). A start assisting conductor (48) for applying an electric field to the inside of said arc tube (12) and at least one second thermal switch (50, 50a, 50b) allow said start assisting conductor (48) to be brought into close contact with and moved away from said arc tube (12). Because of this construction, the non-linear ceramic capacitor is prevented from early deterioration, thus lenghthening the service life of the discharge lamp, and safe restarting is ensured. <IMAGE>