In 1876, Renault decided to make an optical toy for a child. On the basis of Phenakistiscope and Zoetrope, he designed a movable mirror and applied for a patent on December 21, 1877. In this design, 12 mirrors are spliced into a drum shape, and colorful picture strips are installed in it. When the toy rotates, each picture is reflected without complicated mechanical devices. The picture bar shows a clear, bright and undistorted animation effect, and there is no jitter. He rented an apartment in Paris, commercially produced movable mirrors and exhibited them at the 1878 Paris World Expo, which caused a sensation.
in p>1879, he improved the movable mirror and designed the Praxinoscope Théatre. The mirror was placed in a wooden box with a glass viewing hole on it. In 188, he invented the projection movable mirror, the principle of which was the same as the previous design, and added a slide device to project the picture onto the screen, so that many viewers could watch it together. Images are depicted on a disk, as before, with only 12 images.
in December, 1888, he improved the design again and applied for a patent for the optical film machine. This is a large movable mirror, suitable for public projection. The length of the picture bar is extended by using the spool. The image is depicted on the tape strip, with holes punched on both sides, so that it rotates more smoothly. A piece of tape usually has 5-6 pictures.