1654, the German Jew Kishore first described the invention of the slide projector. At first, the shell of the slide projector was knocked into a square box with a chimney-like exhaust pipe at the top and a cylinder installed in front. A sliding convex lens is used in a cylinder to form a simple lens. There is a panel with adjustable focal length between the lens and the tin box, and a light source is installed in the box. The original light source was candlelight. When in use, put the slide projector in a dark room, insert the slide into the groove behind the convex lens, and light the candle. The light source is reflected and converged by the reflector, and the formed light beam is reflected to the curtain wall through the transparent picture and lens.

The earliest slides were made of glass and drawn by hand. /kloc-In the mid-9th century, after the invention of celluloid film in the United States, it began to make slides by pad printing.