Patent ID: 6094015
Filing Date: 2000-07-25
Classification: H01J,Y10S

Abstract:
An illumination unit, comprising:a high-frequency supply having a first output and a second output for supplying respective high-frequency voltages varying relative to ground, said voltages having the same magnitude and being in phase opposition, said high-frequency supply being provided with a further output which is substantially free of high-frequency voltage variations relative to ground; anda low-pressure discharge lamp having a tubular discharge vessel with opposite ends and an ionizable filling, which discharge vessel comprises a first external electrode and a second external electrode, which are arranged at respective said ends the discharge vessel and which are connected to, respectively, the first output and the second output of the supply,wherein the discharge vessel of the low-pressure discharge lamp comprises a further external electrode which is centrally arranged between the ends of the discharge vessel and which is connected to the further output of the supply.