Systems and methods for fabricating three-dimensional objects

Patent metadata

Field	Value
Publication number	US-9561622-B2
Application number	US-201314076161-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	May 5, 2008
Publication date	Feb 7, 2017
Grant date	Feb 7, 2017

Abstract

Systems and methods for fabricating three-dimensional objects. The system includes an optical imaging system providing a light source; a photosensitive medium adapted to change states upon exposure to a portion of the light source from the optical imaging system; a control system for controlling movement of the optical imaging system, wherein the optical imaging system moves continuously above the photosensitive medium. The method includes moving a maskless optical imaging system providing the light beam in a continuous sequence; presenting the light beam on a portion of the photosensitive medium; lowering a plate upon which the photosensitive medium resides; and applying a new layer of the photosensitive medium.

First claim

What is claimed is:

1. A system for fabricating a three-dimensional object, the system comprising:
a photosensitive medium adapted to change states upon exposure to a light source;
an optical imaging system, configured to continuously move above the photosensitive medium, and having the light source and a spatial light modulator;
a control system for controlling movement of the optical imaging system; and
an XY motion stage with sub-micron position resolution, configured to move the optical imaging system.

2. The system of claim 1 , the optical imaging system comprising a plurality of light sources and comprising a plurality of spatial light.

3. The system of claim 1 , the photosensitive medium selected from the group consisting of: a photopolymer, a polymer-ceramic matrix, a polymer-ceramic precursor matrix, and mixtures thereof.

4. The system of claim 1 , the spatial light modulator comprising a digital micromirror device.

5. The system of claim 1 , the spatial light modulator selected from the group consisting of: a liquid crystal display, a grating light valve, and a digital mirror device.

6. The system of claim 1 , the spatial light modulator comprising a digital mirror device having a plurality of pixels, each pixel configured to reflect light from the light source to the projection lens in a first state and away from the projection lens in a second state.

7. The system of claim 1 , the light source comprising an ultraviolet light source.

8. The system of claim 7 , the ultraviolet light source selected from the group consisting of: a mercury vapor lamp, xenon lamp, violet laser diode, diode pumped solid state laser, frequency-tripled Nd:YAG laser, and XeF excimer laser.

9. The system of claim 1 , wherein the optical imaging system further comprises a projection lens having a reduction ratio between about 1 and about 50.

10. The system of claim 1 , further comprising a plurality of spatial light modulators.

11. A method, comprising:
continuously moving the optical imaging system of claim 1 over a first surface of a photosensitive medium; and
projecting, with the optical imaging system, an image of a cross-section of a three-dimensional object onto a portion of the first surface of the photosensitive medium while the optical imaging system is moving.

12. The method of claim 1 , wherein the optical imaging system comprises a pulsed light source, wherein the optical imaging system receives a plurality of images corresponding to portions of the cross section, and wherein the optical imaging system projects a single image from the plurality of images with each pulse of the pulsed light source on to the first surface of the photosensitive medium.

13. The method of claim 1 , further comprising the step of sweeping a layer of the photosensitive medium across the first surface of the photosensitive medium to produce a second surface of the photosensitive medium.

14. The method of claim 1 , wherein the step of projecting an image of a cross section comprises projecting a screened grayscale image.

15. The method of claim 14 , wherein the screened grayscale image is produced using a halftone process.

16. The method of claim 14 , wherein the screened grayscale image is produced using a stochastic screening process.

Assignees

• Das Suman
• Yuan Dajun
• Rudraraju Anirudh
• Cilino Paul
• Georgia Tech Res Inst

Inventors

• Das Suman
• Yuan Dajun
• Rudraraju Anirudh
• Cilino Paul

Classifications

• B33Y10/00

  Processes of additive manufacturing · CPC title

• G03F7/70291

  Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices · CPC title

• B33Y30/00

  Apparatus for additive manufacturing; Details thereof or accessories therefor · CPC title

• B29C64/40

  Structures for supporting 3D objects during manufacture and intended to be sacrificed after completion thereof · CPC title

• B22C9/24

  for hollow articles · CPC title