ELECTRODE, DISCHARGE LAMP, AND LIGHTING DEVICE

摘要

PROBLEM TO BE SOLVED: To provide a long-life electrode, by which waste of electrode material can be omitted, a transition time from glow discharge to arc discharge can be shortened, and blackening of a bulb inside wall of a lamp can be prevented, a discharge lamp, and a lighting device including this lamp. SOLUTION: An electrode 1A is provided with a bottomed cylindrical container 2 consisting of conductive high melting point material and having a recess part 3A, which is arranged on the front face side and provided with an inside wall 31 circumferential length longer than the front face circumferential length, thermal electron emitting parts 4... made of granular semiconductive ceramics filling the inside of the recess part 3A of the container 2, and a retaining member 5 for the container 2. The electrode 1A is hermetically arranged in a discharge lamp FL. The discharge lamp FL is mounted in a lighting device 9.