Techniques for generation and direction of light in additive fabrication and related systems and methods
According to some aspects, techniques that address one or more drawbacks of laser-based optical systems in additive fabrication devices are described. In some aspects, an additive fabrication device may include one or more variable focus lenses that may be operated (e.g., actuated) during fabrication to adjust the focus, and thereby the spot size, of a laser beam. In some aspects, an additive fabrication device may comprise a laser array, such as a plurality of vertical-cavity surface-emitting lasers (VCSELs), that may be operated to direct light into a build region, rather than using a single laser beam, such as a single diode laser. In some aspects, an additive fabrication device may comprise a container that includes a flexible display film, such as a flexible LCD screen, which may be operated to direct light into the container to thereby cure a liquid photopolymer therein.
1. An additive fabrication device comprising:
a build platform with a build surface for forming an object thereon, wherein the build platform is configured to move in a vertical direction relative to the additive fabrication device;
a container for holding liquid photopolymer that is polymerizable on exposure to radiation, the container comprising:
an interior bottom surface;
sides connected to the interior bottom surface; and
a flexible display film extended between the sides of the container, wherein the flexible display film is configured to produce radiation to cure selected portions of the liquid photopolymer in the container, and
at least one controller configured to operate the flexible display film as a light source to produce said radiation from selected regions of the flexible display film to cure the selected portions of the liquid photopolymer and thereby form a layer of cured liquid photopolymer in contact with the interior bottom surface of the container and the build surface of the build platform and/or a previously formed layer of cured liquid photopolymer.
2. The additive fabrication device of claim 1 , wherein the flexible display film forms at least part of the interior bottom surface of the container.
3. The additive fabrication device of claim 1 , wherein the container further comprises a first film extended between the sides of the container, and wherein the first film forms at least part of the interior bottom surface of the container.
4. The additive fabrication device of claim 1 , wherein the flexible display film is a flexible LCD display, a flexible OLED display, or a flexible micro-LED display.
5. The additive fabrication device of claim 1 , wherein the flexible display film is configured to emit ultra-violet radiation or near-ultra-violet radiation.
6. The additive fabrication device of claim 1 , wherein the additive fabrication device further comprises a movable stage configured to move in a lateral direction relative to the additive fabrication device underneath the container.
7. The additive fabrication device of claim 6 , wherein the movable stage is configured to contact the flexible display film and produce a flat portion of the flexible display film above the movable stage.
8. The additive fabrication device of claim 6 , wherein the movable stage comprises a plurality of lasers configured to produce radiation to cure the liquid photopolymer in the container, and wherein the flexible display film is transparent to the radiation produced by the plurality of lasers.
9. The additive fabrication device of claim 8 , wherein the plurality of lasers are vertical-cavity surface emitting lasers (VCSELs).
10. The additive fabrication device of claim 8 , wherein the plurality of lasers are configured to emit ultraviolet light.
11. The additive fabrication device of claim 8 , wherein the plurality of lasers are configured to emit infrared light.
12. The additive fabrication device of claim 8 , wherein the plurality of lasers are arranged in a single row.
13. The additive fabrication device of claim 8 , wherein the plurality of lasers are arranged in a two-dimensional array.
14. The additive fabrication device of claim 8 , wherein the plurality of lasers and the flexible display film are configured to cure different portions of the liquid photopolymer simultaneously.
15. The additive fabrication device of claim 8 , further comprising a variable focal length lens situated between the plurality of lasers and the interior bottom surface of the container, wherein the variable focal length lens is configured to adjust a focal length according to a selected plurality of different spot sizes.