Belgian physicist Joseph Plateau unveiled an invention called the Phenakistoscope, a device that is largely considered to be the first mechanism for true animation. The simple gadget relied on the persistence of vision principle to display the illusion of images in motion.
He was the first person to demonstrate the illusion of a moving image. To do this he used counter rotating disks with repeating drawn images in small increments of motion on one and regularly spaced slits in the other. He called this device of 1832 the phenakistoscope.
The phenakistoscope used a spinning disc attached vertically to a handle. Arrayed around the disc’s center were a series of drawings showing phases of the animation, and cut through it were a series of equally spaced radial slits. The user would spin the disc and look through the moving slits at the disc’s reflection in a mirror. The scanning of the slits across the reflected images kept them from simply blurring together, so that the user would see a rapid succession of images that appeared to be a single moving picture.