ELECTRODE FOR DISCHARGE LAMP

摘要

PURPOSE:To obtain the considerably excellent starting characteristic and the flux maintaining factor by making the average grain size of the electron emission material for a discharge lamp electrode having the electron emission substance to be specific times that of the heat-resistant metal. CONSTITUTION:In an electron emission subsistance where the mixing ratio of W is higher than 50wt%, the compound such as Sc2O3 or Sc2WO6 produced through the reaction between Sc2O3 and W during the electrode heating process is reacted with W under high temperature during the lighting of lamp to form the free electron of Sc which will reach through the grain field of W to the surface of the emission subsistance to lower the work factor of the electrode. Consequently the average grain size of the electron emission subsistance is made to be 0.01-5 times that of the heat-resistanct metal. Consequently excellent starting characteristic and the deterioration characteristic is achieved resulting in a discharge lamp where there is no incomplete starting.