The set of early patents established the way industry created animated films using backgrounds, cels and a rostrum camera.

That process, in itself, did not make the generation of cels any easier and resulted in films that were mostly flat in 2 dimensions with little use of perspective.

Five patents illustrate the advances in the period between 1917 and 1940.

  • 1,242,674:Method of Producing Moving Picture Cartoons, Rotoscoping, Max Fleischer, 9 October, 1917
  • 1,380,298:Process and Apparatus for Producing Moving Picture Films , Earl Hurd, 31 May, 1921
  • 2,054,414: Art of Making Motion Picture Cartoons, Rotograph , Max Fleischer, 15 September 1936, (Filed 2 November 1933)
  • 2,130,541: Art of Making Motion Picture Cartoons, Masking, Max Fleischer, 14 December, 1936
  • 2,201,689: Art of Animation, Multiplane Camera , Walt Disney, 21 May, 1940

The Fleischer Rotoscope was used to copy a live-action shot into animated drawings. The USA had entered the 1914-18 war in 1917 and needed training films to show how various machine guns and other artillery worked. The Bray Studios were commissioned to make the films. Later, rotoscoping was used to emulate live dancers etc with animated characters.

The Earl Hurd patent eased the problem of animating a character walking towards the camera where the perspective needed to be changed appropriately.

In 1921, Max and Dave Fleischer set up their own studios. The rotograph effectively set up a camera in a miniature set with background objects at different distances thus allowing the main characters to move in a pseudo 3D-world. The film Little Dutch Mill is a good example of rotograph output produced in 1934 while the patent was still pending. The rotograph also appears in this Paramount newsreel about Fleischer Studios.

The Disney patent is for the multi-plane camera that produced results similar to that of the rotograph but was a more sophisticated product. The foreground animation could occur on multiple levels with their own lighting and focus and move at different speeds. The original four level version is on the Disney lot in Burbank. The camera needed a team of operators to run it.