HIGH-PRESSURE SODIUM LAMP, HIGH-PRESSURE SODIUM LAMP LIGHTING DEVICE, AND LIGHTING SYSTEM

摘要

PROBLEM TO BE SOLVED: To minimize the changes in luminous flux maintenance factor in lighting and hold stable brightness by controlling the bulb wall loading of an arc tube in the specified value, based on the power and the inner diameter of the arc tube and the distance between electrodes. ;SOLUTION: Electrodes 2, 3 are sealed airtightly to the sealed parts of two arc tubes 1, whose both ends are sealed. The electrodes 2, 3 are arranged concentrically facing at specified intervals, and high-pressure sodium is sealed in the arc tube 1. Power supply bodies 4, 5 are connected to the electrodes 2, 3 respectively, and the power supply bodies 4, 5 are airtightly extended to the outside from the sealed end parts. When the power of the arc tube 1 is represented by WL(W), the inside diameter by (d)(cm), the distance between electrodes by Led(cm), bulb wall loading Z=WL/(π×d×Led) of the arc tube 1 is specified to 15 W/cm² or less based on experiments. A starter which causes pulse voltage for starting a lamp is preferably installed on the outside or the inside of the lamp.;COPYRIGHT: (C)1999,JPO