4.6 Displays

Section 2.1 introduced displays as devices that stimulate a sense organ, which in this chapter is the human eye. What should we consider to be the first visual displays? Paintings from Section 1.3 as early instances of displays, but they have the unfortunate limitation that they display a single image in their lifetime. The ability to change images, ultimately leading to motion pictures, was first enabled by projection technologies. The camera obscura principle was refined into a magic lantern, which was invented in the 17th century by Christiaan Huygens. Popular until the 19th century, it allowed small, painted images to be projected onto a wall through the use of lenses and a bright light source. By the end of the 19th century, motion pictures could be shown on a large screen by a mechanical projector that cycled quickly through the frames.