First 3D-printing patent

The first patent for a 3D printer was filed on 12 July 1967 in Denmark by Wyn Kelly Swainson, a 27-year-old American graduate student. The patent, called "Method of Producing a 3D Figure by Holography" envisaged a system whereby a three-dimensional object could be scanned using a pair of laser interferometers and its dimensions transferred to a computer. This computer would then feed the data on the object's shape to a second pair of lasers, which would reproduce it by selectively hardening a 3D shape in tank of light-sensitive plastic.

Swainson was an English Literature student, who came to the idea after asking himself why there was no way to make 3D copies of sculptures, like photographs of paintings. He taught himself enough science to start working on possible methods by spending months in the British Library Reading Room, reading patents and scientific journals. His studies led him to photopolymers, a class of plastics which remain liquid until exposed to UV or visible light. In his patent (later refined as US patent #4,041,476 "Method, Medium and Apparatus for Producing a Three-Dimensional Figure product") he proposed creating objects using two intersecting lasers operating at different frequencies. This way the plastic would only harden in the specific place where the lasers met.

Although it represented a visionary glimpse of the technology that was to come, the patent was not accompanied by a working prototype and was notably light on practical details in certain regards. The "computer" stage, in particular, was a black box with no explanation of how it might work. Swainson continued to work on 3D-printing projects throughout the 1970s and early 1980s, founding a company – the Formigraphic Engine Corporation – and carrying out research for DARPA and other agencies. His work never resulted in a commercially viable product, however, and was eclipsed by Charles Hull's invention of stereolithography in the mid-1980s. He died in 1988, aged 48.