INCANDESCENT LAMP WITH BULB HAVING IR REFLECTING FILM

摘要

ABSTRACT OF THE DISCLOSUREThis invention relates to an incandescent lampbulb comprising a visible light transmitting and infra-red ray reflecting film formed on at least either oneof the inside and outside of a tubular, transparentbulb, said film being composed of a lamination ofalternate high and low refractive index layers, whereinthe optical film thickness of any one of the highreflective index layers ranges from 0.21 to 0.31 µ,that of the topmost low refractive index layer rangesfrom 1/2 x 0.21 to 1/2 x 0.31 µ, that of at least onelow refractive index layer ranges from 2 x 0.21 to2 x 0.31 µ, and that of any remainder low refractiveindex layer ranges from 0.21 to 0.31 µ.