Patent ID: 9607821
Date: 2017-03-28
CPC Classifications: H01J,H01K,Y02B

Claim:
1. A lamp having a rated wattage, the lamp comprising: a light-transmissive envelope comprising a light-transmissive material; a tungsten-halogen capsule housing a tungsten filament, wherein said tungsten-halogen capsule is housed inside the light-transmissive envelope; and a coating being disposed on a surface of the light-transmissive envelope or doped in the light-transmissive material, a concentration of the coating being arranged so that the lamp has a color rendering index of at least 50, the lamp has a correlated color temperature from 2400K to 2800K, and the lamp has a lumen per watt of at least 75% of a general service incandescent lamp having the rated wattage's lumen per watt wherein the coating decreases the correlated color temperature of the lamp and wherein the coating comprising about 67.5-66% precipitated silica, 30.5-29.5% aluminum silicate pigment, 0.35-2.44% CrSn pink, 0.05-0.36% red iron oxide, and 1.6-1.75% coupling agents.