Abstract: Reliable starting of a fluorescent lamp that is designed to emit light of a selected color (red, for example) is achieved by using a thin transparent coating of conductive material (such as tin oxide) on the inner surface of the glass envelope in combination with a first overlying layer of a suitable light-filtering pigment material and a second overlying layer of a suitable phosphor. The resulting multi-layered arrangement of such materials and the phosphor eliminates the need for including additives (such as admixed silica and barium sulfate) in the phosphor coating as starting aids and solves the problems of poor light output and unreliable starting which are created by the use of such additives. Multiple layers of pigment material having the proper coating density can also be used.

Abstract: Fluorescent lamp incorporates tin oxide conductive coating on the envelope interior surface and the lamp also incorporates phosphor means comprising manganese-activated zinc silicate phosphor, which may be used as a blend constituent. The lamp is processed in such a manner as to improve the performance of the zinc silicate phosphor. In order to improve the adherence of the phosphor to the tin oxide conductive coating, the tin oxide is overcoated with a film of sub-micron-size aluminum oxide and, in accordance with the present processing, there is included with the aluminum oxide finely divided antimony oxide. The phosphor is then overcoated onto the mixed film of aluminum oxide and antimony oxide, and during the later lehring processing of the coated phosphor, the antimony oxide is volatilized to contact the zinc silicate phosphor to improve the performance thereof.

Abstract: Special commercially available fluorescent lamps of warm-white correlated color temperature of about 3000.degree. K. have both good coloring index and efficacy. These lamps utilize as the light-emitting component a special three-component phosphor blend having emissions principally confined to the wavelength regions of from 430 nm to 485 nm, from 515 nm to 570 nm, and from 588 nm to 630 nm. This phosphor blend is relatively expensive and to decrease expense, it is known to utilize an undercoat of halophosphate phosphor of the same emission color, which decreases the amount of expensive phosphor required.

Abstract: Improved adhesion of the phosphor coating in a fluorescent lamp having a transparent film of conductive material (such as tin oxide) on the inner surface of the bulb is obtained by adding small but correlated amounts of finely-divided aluminum oxide, calcium nitrate, and ammonium nitrate to the water-base phosphor-coating composition. The combination of additives bonds the phosphor particles to the bulb despite the intervening layer of tin oxide and the lower lehring temperature required to preserve its conductivity. When the conductive film is composed of a material which can tolerate higher lehring temperatures, other additives such as barium nitrate, cadmium nitrate and strontium nitrate can be substituted for or admixed with the calcium nitrate.