received by the International Bureau on 23 July 2018 (23.07.2018)

1. An apparatus for forming three-dimensional objects by photo-curing a photo-curing liquid polymer by exposure to a radiation, comprising a tank for containing the liquid polymer, said tank including a base having a transparent opening therein, and a collimated light source to emit said radiation through said transparent opening in said base, by which radiation said photo-curing liquid polymer undergoes curing, said collimated light source comprising an array of light emitting diode (LED) sources, an array of baffles, and an array of lenses, said baffles arranged so as to limit a beam width of each individual LED source in the array of LED sources to approximately a diameter of a lens of the array of lenses, the array of lenses being located one focal length from said array of LED sources.

2. The apparatus for forming three-dimensional objects according to claim 1, wherein at least some of said LED sources are configured to emit radiation at a wavelength between 400 - 700 run.

3. The apparatus for forming three-dimensional objects according to claim 2, wherein at least some of said LED sources are configured to emit radiation at a wavelength of 410 nm.

4. (Cancelled)

5. The apparatus for forming three-dim ens ional objects according to claim 2, wherein one or more of said LED sources are configured to emit radiation at a plurality of wavelengths.

6. (Cancelled)

7. The apparatus for forming three-dim ens ional objects according to claim 2, wherein said collimated light source further comprises a liquid crystal display ("LCD") said LCD positioned between said array of LEDs and an area within said tank within which an object undergoes fabrication by photo-curing of said photo-curing liquid polymer.

8. The apparatus for forming three-dimensional objects according to claim 7, wherein said LCD includes a plurality of filters, each filter of the plurality of filters corresponding to one of said wavelengths of emitted radiation.

9. The apparatus for forming three-dimensional objects according to claim 2, wherein one or more of said LED sources comprises a plurality of LED emitters, each of said emitters configured to emit radiation at one or more wavelengths.

10. The apparatus for forming three-dimensional objects according to claim 1, wherein said LED sources of said collimated light source are organized as a plurality of LED groups, and, corresponding to each of the LED groups is

(i) one of said baffles configured to constrain and direct a first beam of electromagnetic radiation propagating from the LED group;

(ii) a lens arrangement of said lens array configured to receive the first beam of electromagnetic radiation, and project a second beam of electromagnetic radiation, said second beam of electromagnetic radiation being characterized by substantially parallel light rays.

11. The apparatus for forming three-dimensional objects according to claim 10, wherein each of the plurality of LED groups comprises more than one LED.

12. A method for forming three-dimensional objects by photo-curing a photo-curing liquid polymer exposed to a radiation, wherein said three-dimensional objects form by growth, due to the progressive curing of said photo-curing liquid polymer, in a space between a sheet transparent to said radiation and a supporting plate, that is, a portion already formed of said objects, said supporting plate progressively moving away from said transparent sheet, characterized in that said photo-curing liquid polymer undergoes curing by irradiation from a collimated light source which includes an array of light emitting diode (LED) sources, an array of baffles, and an array of lenses, said baffles arranged so as to limit a beam width of each individual LED source in the array of LED sources to approximately a diameter of a lens of the array of lenses, where the array of lenses is located one focal length from said array of LED sources.

13. (Cancelled)

14. The method for forming three-dimensional objects according to claim 12, characterized in that said LED sources emit radiation at a wavelength between 400 - 700 ma

15. (Cancelled)