The history of the digital camera starts with the evolution of the television, back in the 1940's and 50's. When television was first broadcast it was all live. A way had to be found to record the images being broadcast. In 1951 Bing Crosby laboratories introduced the VTR, which recorded the electrical impulses onto magnetic tape. By 1956 the VTR technology worked well, and it began to have a large impact on the television industry. This, tied in with the development of computers in the 1950's started the digital age.
The next large step occurred with NASA in the 1960's. Before NASA sent astronauts to the moon, probes were sent to map the surface of the moon. These probes sent back analogue signals to earth, NASA engineers found that the transmissions were too weak to compete with natural radio sources in the cosmos. Current television receivers could not decipher the images sent back from the moon, so NASA engineers had to find a way to enhance and sharpen the images. Images were processed through a computer and turned into a digital signal, and all noise and corruption of the data was removed. By the time Apollo went to the moon, transmissions were coming back crystal clear.
After that the cold war accelerated development of digital imaging, mostly used for spy satellites and imaging systems.
In 1995 Kodak released the dc40 and at under a $1000 it was the first digital camera marketed for consumers. The Apple QuickTake 100 was also made available at the same time. Both connected to the computer via serial cable.