Global Patent Index - EP 0670588 B1

EP 0670588 B1 19970514 - Metal halide lamp

Title (en)

Metal halide lamp

Title (de)

Metallhalogenidlampe

Title (fr)

Lampe aux halogénures métalliques

Publication

EP 0670588 B1 19970514 (EN)

Application

EP 94301523 A 19940302

Priority

  • EP 94301523 A 19940302
  • JP 25628792 A 19920925

Abstract (en)

[origin: EP0670588A1] A metal halide lamp includes a quartz sealed tube having a pair of electrodes using tungsten as the base material. Argon gas, mercury, at least one kind of rare earth metal (e.g., dysprosium, holmium, thulium, neodymium, and erbium), bromine, iodine, and an alkali metal, e.g., cesium, are contained in the sealed tube. The total number of moles of bromine and iodine in the sealed tube is in excess of the number of moles of the rare earth metal. Accordingly, tungsten which is liberated from the electrode during electric discharge can be captured mainly by iodine. A reaction between silicon dioxide, which is a constituent component of the sealed tube, and tungsten is prevented, thereby preventing blackening of the tube wall of the sealed tube.

IPC 1-7

H01J 61/20

IPC 8 full level

H01J 61/20 (2006.01)

CPC (source: EP)

H01J 61/20 (2013.01)

Designated contracting state (EPC)

DE FR GB IT SE

DOCDB simple family (publication)

EP 0670588 A1 19950906; EP 0670588 B1 19970514; JP H06111769 A 19940422

DOCDB simple family (application)

EP 94301523 A 19940302; JP 25628792 A 19920925