Biplane Filament Construction—A High Intensity Incandescent Lamp Light Source for Motion Picture Projection

J. T. Mili

Manufacturers of motion picture projectors have been continuously demanding increasingly brighter and more uniform light sources. The biplane staggered filament construction, consisting of two parallel rows of coils, so placed that the coils in one plane fill the spaces between coils in the other, is now being presented as the lamp manufacturer's answer to this demand of the industry. A report is presented on comparative tests made with monoplane and biplane filament lamps ranging in wattage from 200 to 1000, with several types of optical systems. A description of the methods pursued in taking screen lumen readings and making bulb temperature measurements is also included.

Print ISSN
Published
1932-07
Content type
Original Research
DOI
10.5594/J05498