The Economics of Projector Lamps for Advertising Purposes

Although the trend in projection lamp development has been toward high-intensity, short-life lamps, the need for a lamp that can be operated for long periods of time, such as in advertising projectors, has arisen. The design and operating characteristics of such a lamp are described, together with the influence of airway beacon practice, the problem of existing projectors, projector lens limitations, and the effect of voltage change.