LOW-VOLTAGE DISCHARGE LAMP AND BACKLIGHT DEVICE USING SAME

A low-voltage discharge lamp (1) comprising a glass tube (2) having an inner diameter of 1 to 5 mm and a pair of electrodes (3) disposed at both ends of the glass tube (2), wherein the electrodes (3) contain at least one transition metal selected from the transition metals of groups IV to VI, and mercury and rare gases including argon and neon are sealed in the glass tube (3). The relationships between the cathode glow discharge density (J) and the composition index α of the rare gases sealed in are α <= J = I/(S·P2) <= 1.5α (where S is the effective discharge area (mm2) of the electrodes, I is the effective value of the lamp current (mA), P is the pressure (kPa) of the rare gases, and α is the index of the rare gasses and is a constant expressed by the formula α=(90.5A+3.4N)x10-3 if the sum of the composition ratio A of the argon and the composition ratio of the neon is A+N=1.). Sputtering of the small electrodes is suppressed, the life is prolonged because the consumption of the rare gasses is reduced, and degradation of luminous flux is prevented. © KIPO & WIPO 2007