Systems And Methods For Fabricating Three-Dimensional Objects

Abstract

A system including a container for holding a photosensitive medium adapted to change states upon exposure to a light source, an optical imaging system, configured to move above the container holding the photosensitive medium, and having the light source, and a control system configured to: slice a digital model of a three-dimensional object into a slice having a cross-section, generate a build cross-section by filling a two-dimensional image with one or more copies of the cross-section, add to the build cross-section a conformal lattice to fill space in the build cross-section around the one or more copies of the cross-section, and control movement of the optical imaging system above the container to cure a portion of the photosensitive medium corresponding to the build cross-section to produce a layer of a three-dimensional object.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. patent application Ser. No. 16 / 113,338 filed 27 Aug. 2018, which is a divisional of U.S. patent application Ser. No. 15 / 419,600 filed 30 Jan. 2017, which is a continuation of U.S. patent application Ser. No. 14 / 076,161 filed 8 Nov. 2013, which claims benefit, under 35 USC § 119(e), of U.S. Provisional Application Ser. No. 61 / 723,991 filed 8 Nov. 2012 and is also a continuation-in-part of U.S. patent application Ser. No. 12 / 435,776 filed on 5 May 2009, which claims benefit, under 35 USC § 119(e), of U.S. Provisional Application Ser. No. 61 / 050,383 filed 5 May 2008. This application is also related to U.S. application Ser. No. 14 / 076,151 filed 8 Nov. 2013, U.S. application Ser. No. 14 / 132,835 filed 18 Dec. 2013, and International Patent Application No. PCT / US13 / 69349 filed 8 Nov. 2013. The entire contents and substance of the above applications are hereby incorporated by reference in their entireti...

AI Technical Summary

Benefits of technology

The present invention provides improvements to conventional systems and methods for fabricating polymer materials. These improvements overcome limitations, such as polymerization shrinkage and liquid polymer movement, to result in increased resolution and speed of fabrication. The improvements include a new polymer container design, a light modulation process, and light patterns. In summary, the invention improves the polymer material fabrication process to achieve better results.

Problems solved by technology

While effective, the use of physical masks in photolithography has numerous drawbacks, including the cost of fabricating masks, the time required to produce the sets of masks needed to fabricate semiconductors, the diffraction effects resulting from light from a light source being diffracted from opaque portions of the mask, registration errors during mask alignment for multilevel patterns, color centers formed in the mask substrate, defects in the mask, the necessity for periodic cleaning, and the deterioration of the mask as a consequence of continuous cleaning.

While maskless photolithography systems address several of the problems associated with mask-based photolithography systems, such as distortion and uniformity of images, problems still arise.

Notably, in environments requiring rapid prototyping and limited production quantities, the advantages of maskless systems as a result of efficiencies derived from quantities of scale are not realized.

Further, while maskless photolithography systems are directed to semiconductor manufacturing, these prior art systems and methods notably lack reference to other applications lending themselves to maskless photolithography techniques.

This mask-based photopolymer process suffers from the disadvantages of mask-based photolithography methods, including the requisite need for many different masks, long lead time for mask creation, inability to modify masks, and the degradation of masks used in the manufacturing process.

If molds are needed, these must be fabricated as well, which may take considerable and valuable time.

The design and review process is often tedious and tooling for the creation of the prototype is laborious and expensive.

On the other hand, one conventional and significant disadvantage of rapid prototyping, other than initial costs to implement technology, is that the time associated with the creation of each part may still be longer than desired.

Because creation of the part occurs in a point-by-point, layer-by-layer process, the time necessary to produce a single part may become excessive.

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