A carousel slide projector is a slide projector that uses a rotary tray to store slides, used to project slide photographs and to create slideshows. It was first patented on May 11, 1965, by David E. Hansen of Fairport, New York. Hansen was an industrial designer at the Eastman Kodak Company. A patent for the rotary tray was granted in 1966 after a 1962 application by the Eastman Kodak Company. The original concept for the carousel slide projector is credited to Italian-American Louis Misuraca, who brought his design to the Kodak company, and sold it for a lump sum. Kodak released their first Carousel projector, the Model 550, in 1961 and sold it until 1966. The 1963 Carousel Model S (Carousel-S), a professional model sold only in Germany, was designed by Hans Gugelot and Reinhold Häcker for Kodak AG in Stuttgart and is in the permanent collection of the Museum of Modern Art. Physical form A separate, circular tray holds several (usually 80 or 140) 35mm slides, and is filled with each slide placed in upside down and backwards, so that the image is projected with the correct orientation. The tray has a metal plate on the bottom with an opening approximately wide, barely large enough to pass a single slide to the projection gate below it. The projector body contains a motor which rotates the plastic main body of the tray (containing the slides) while the metal plate is fixed with the opening over the projection gate. As the tray is advanced, a reciprocating mechanism pushes the currently loaded slide back out into the tray, then the tray is rotated, dropping the next slide into position between the light source and lens. A common series of carousel projectors with a horizontally mounted tray was introduced in the spring of 1962 by Kodak (Kodak Carousel/Ektagraphic). The earliest Carousel models (mostly known as the 500-series) are compatible only with the 80-slide trays. The Kodak system offered three advantages over the straight-tray, horizontal-feed systems that were then common on the market. The Carousel tray held slides in place with a locking ring on its hub, preventing slides from accidentally spilling out of the tray if it was dropped. By using gravity to lower the slide into the projector, the chance of jamming was greatly reduced, since a warped slide would not descend past the point at which it encountered resistance in the