Patent ID: 6608440
Filing Date: 2003-08-19
Classification: H01J

Abstract:
A high pressure discharge lamp, comprising:a quartz glass bulb; and a pair of electrodes, each electrode of said pair of electrodes being disposed so as to be opposite the other in said quartz glass bulb, wherein at least mercury and a halogen gas are airtightly sealed in said quartz glass bulb, and the partial pressure of oxygen (O) in said quartz glass bulb is about 2.5Ã—10âˆ’3 Pa or less, the partial pressure of said halogen gas in said quartz glass bulb is in the range between about 1Ã—10âˆ’6 &mgr;mol/mm3 and 1Ã—10âˆ’8 &mgr;mol/mm3, and said pair of electrodes contain potassium oxide in the range between about 20 ppm and 40 ppm.