William Kennedy Laurie Dickson (August 3, 1860 - September 28, 1935) was a Scottish inventor who is credited with the invention of the motion picture camera under the employ of Thomas Edison. In fact, Edison saw very little value in the contraption, but thought that it might be served to endorse his phonograph. On January 7, 1894 Dickson received a patent for motion picture film. It is generally believed that Dickson produced the world's first film, "Dickson Greeting", in 1891. Shortly afterwards, after a great deal of debate with Edison and Menlo Park colleague Jonathan Campbell, Dickson switched from the 19mm width, single sprocket film he was using, to the more stable 35mm double-sided sprocket film. Edison didn't see the need or benefit for redesigning the equipment to accept the larger negative, but Dickson and Campbell believed it was essential if the technology was to advance. 35mm double-sided sprocket film is still used as today's standard. In 1895 he left Edison to form the American Mutoscope and Biograph Company, before returning permanently to work in Britain in 1897.