While digital photography has only recently become mainstream, the late 20th century saw many small developments leading to its creation.
The first image of Mars was taken as the Mariner 4 flew by it on July 15, 1965, with a camera system designed by NASA/JPL.
While not what we usually define as a digital camera, it used a comparable process.
It used a video camera tube, followed by a digitizer, rather than a mosaic of solid state sensor elements.
This produced a digital image that was stored on tape for later slow transmission back to Earth.
The real history of digital photography as we know it began in the 1950s.
In 1951, the first digital signals were saved to magnetic tape via the first video tape recorder.
A mere six years later, in 1957, the first digital image was produced through a computer by Russell Kirsch.
It was an image of his son - but to the world it was a giant leap forward for all of science and eventually the field of photography. In the late 1960s, Willard S. Boyle and George E. Smith, two physicists with Bell Labs, invented the charge-coupled device (CCD), a semiconductor circuit later used in the first video camera for television broadcasting.
Their invention, which in 2009 won them the Nobel Prize in Physics, was used by Steven Sasson, an engineer at Eastman Kodak, who in 1975 created the world's first digital camera.
Source: Wikipedia, the free encyclopedia.