A movie projector

A movie projector is an opto-mechanical device for displaying moving pictures by projecting them on a projection screen. Most of the optical and mechanical elements, except for the illumination andsound devices, are present in movie cameras.
The first machine patented in the United States that showed animated pictures or movies was a device called the «wheel of life» or «zoopraxiscope».Patented in 1867 by William Lincoln, moving drawings or photographs were watched through a slit in the zoopraxiscope. However, this was a far cry from motion pictures as we know them today. Modern motionpicture making began with the invention of the motion picture camera.

The Frenchman Louis Lumiere is often credited as inventing the first motion picture camera in 1895. But in truth, several othershad made similar inventions around the same time as Lumiere. What Lumiere invented was a portable motion-picture camera, film processing unit and projector called the Cinematographe, three functionscovered in one invention.

The Cinematographe made motion pictures very popular, and it could be better be said that Lumiere’s invention began the motion picture era. In 1895, Lumiere and his brotherwere the first to present projected, moving, photographic, pictures to a paying audience of more that one person.

Design

Movie projectors consist of four primary sections including the spoolassembly, lamp assembly, lens assembly, and audio assembly.

Spool assembly

The primary purpose of the spool assembly is to move the film through the projector. While the motion appears continuous,there is actually a slight pause after each frame. This allows light to be passed through the image and projected on the screen. The spool assembly is made up of all the parts related to storing andmoving the film.

Lamp assembly

The lamp assembly includes all of the parts related to illuminating the image on the film. The key element is the light source. Modern movie projectors use a…