Patent ID: 7358675
Filing Date: 2008-04-15
Classification: H01J

Abstract:
1. A low-pressure discharge lamp, comprising: a glass tube having an inner diameter in a range of 1 to 5 mm; and a pair of electrodes disposed at end portions in the glass tube, wherein the pair of electrodes are formed of a material without metal oxides, including at least one transition metal selected from transition metals of Groups IV to VI, mercury and a rare gas containing argon and neon are sealed in an inner portion of the glass tube, and a relationship α≦J≦1.5α is satisfied, where J represents a numerical value obtained from the expression J=I /(S·P 2 ), in which S represents a numerical value of an effective electrode discharge surface area (mm 2 ), I represents a numerical value of a RMS lamp current (mA), P represents a numerical value of the pressure (kPa) of a sealed rare gas, and α represents a numerical value obtained from the expression α=(90.5 Ar+3.4N)×10 −3 where Ar and N represent relative composition ratios of argon and neon in the rare gas and Ar and N satisfy Ar+N=1.