• 3D Printing
  • The Father of 3D Printing: Charles W. Hull

Charles W. Hull (others also called him Chunk Hull) was born on May 12, 1939 in Clifton, Colorado. He graduated from the Grand Junction Center High School in Colorado, in 1961. The University of Colorado received a bachelor's degree in engineering physics.


In 1983, Hull served as vice president of ultraviolet equipment manufacturer Ultraviolet Products, which used ultraviolet light to harden the coating on furniture and paper surfaces. Hull used a variety of UV lamps in the company every day to watch the resin that was originally liquid and solidified as soon as it touched ultraviolet rays. One day he suddenly realized that if he could sweep ultraviolet rays layer by layer on the surface of the photopolymer, making it a solid layer by layer, and stacking these hundreds of thin layers together, he It can make any imaginable three-dimensional object.

On July 16, 1984, three Frenchmen, Alain Le Méhauté, Olivier de Witte, and Jean Claude André tried first to register for the SLA patent. However, they were rejected by the French General Electric Company and the CILAS (Laser Federation) on the grounds that " Lack of commercial application value." Three weeks later, with Hull as inventor, UVP applied for the world's first SLA patent.


On March 11, 1986, Hull obtained a patent authorization, patent number US4575330A. In the patent titled "Apparatus for Production of Three-Dimensional Objects by Stereolithography", he invented the term "stereolithography", abbreviated as SLA, that is, the later stereolithography technique that uses ultraviolet light to catalyze the photosensitive resin layer stacking. forming.

The patents that work in U.S. companies ultimately belong to the company, but Hull's boss has no more ability to support the development of this new technology. So Huhr left UVP and started his own business. In 1986, he established 3D Systems in California (one of the world's two largest manufacturers of 3D printing equipment), and he is committed to commercializing SLA technology. In 1988, 3D Systems produced its first self-developed 3D printer, the SLA-250, which was very bulky and used acrylic materials for photophotography. The launch of the SLA-250 has become a milestone in the history of 3D printing technology. Its design concept and style have affected almost all subsequent 3D printing devices. However, due to the process conditions at that time, its size was very large and the effective printing space was very narrow.

In 1990, 3D Systems repurchased the US4575330A patent from UVP. Hull realized that his technical concept was not limited to liquids. In the resubmitted patents, he emphasized that any “curable material” or “material that can change its physical state” can achieve SLA technology. In 1988, 3D Systems sold its first 3D printer based on SLA technology. Since then, various models of 3D printers have been introduced in the past few decades, including desktops for office and home use and industrial machines suitable for factory applications. The company was registered in Delaware, USA. It was listed on Nasdaq in the United States in the early 1990s. In 2011, the company transferred to the NYSE.

After decades of development, 3D Systems has nearly 1,000 patents. All patents registered in Hull cover many basic technical methods of today's 3D printing technology, such as preparation of slice data using a triangular model (STL file format), and alternate exposure strategies. The 3D printer invented by 3D Systems has entered numerous industrial and commercial applications. The medical industry utilizes the mandible or facial structure model of patients made with 3D Systems printing equipment. The car safety company uses 3D Systems technology to produce crash test robots. The watch industry Prototype evaluation and ergonomic design using 3D Systems technology. All walks of life are enjoying the changes brought about by the 3D printing technology of 3D Systems.


In 1984, Hulr may not have realized at all that his rapid manufacturing patents could be so popular after more than 30 years. In 2014, Hull was nominated for the European Inventors Award, which was awarded to individuals and teams who have made outstanding contributions to the development of human science and technology. In the same year, Hull was elected as the National Inventors Hall of Fame (NIHOF), which also meant that Hulry entered the ranks of celebrities such as Henry Ford and Steve Jobs and became an inventor who had made lasting contributions to mankind.