The Design of a Combination Projector and Viewer for Use with Colored Transparencies

A study of the photographic field has revealed a need for a more versatile method of viewing still color transparencies of 35 millimeter and similar size. The conditions of the market, the consumer preferences, and the sales procedures concerning photographic goods were investigated. The results of these investigations established the criteria upon which the final design was based. The engineering and appearance design of a machine utilizing one optical system for both projecting and viewing the transparencies has been completed and is herein presented. The device is fundamentally a complete projector with the addition of a viewing screen built into the upper case. The optical system projects the picture into a pair of mirrors that turn the light beam up and back onto the viewing screen. For distant projection, the lower mirror drops out of position and permits the picture to be projected through an opening located in the rear of the machine. The optical, electrical, and slide changing systems are housed in a two piece anodized aluminum die cast case.