A limited use of a halogen (fluorine, chlorine, bromine or iodine) gas in the manufacture of an incandescent lamp occurred when John Waring, of the Waring Electric Company, was granted U. S. Patent No. 497,038 on May 9, 1893. The lamp, which had a small amount of bromine in it, was known as the "Novak" and was produced in 1893 and 1894. Apparently the presence of bromine did reduce the degree of discoloration and, in addition, the darkening was greenish in color instead of the usual black1. The basic Edison filament patent, over which so much patent litigation occurred, expired in November 1894; the Novak lamp (shown to the left) probably wasn't manufactured after that date.
A limited use of a halogen (fluorine, chlorine, bromine or iodine) gas in the manufacture of an incandescent lamp occurred when John Waring, of the Waring Electric Company, was granted U. S. Patent No. 497,038 on May 9, 1893. The lamp, which had a small amount of bromine in it, was known as the "Novak" and was produced in 1893 and 1894. Apparently the presence of bromine did reduce the degree of discoloration and, in addition, the darkening was greenish in color instead of the usual black1. The basic Edison filament patent, over which so much patent litigation occurred, expired in November 1894; the Novak lamp (shown to the left) probably wasn't manufactured after that date.
การแปล กรุณารอสักครู่..