Systems and methods for fabricating three-dimensional objects

• US 8,636,496 B2
• Filed: 05/05/2009
• Issued: 01/28/2014
• Est. Priority Date: 05/05/2008
• Status: Active Grant

• Current Assignee: Board of Regents of the University of Michigan (University of Michigan), Georgia Tech Research Corporation (University System of Georgia)
• Original Assignee: Board of Regents of the University of Michigan (University of Michigan), Georgia Tech Research Corporation (University System of Georgia)
• Inventors: Das, Suman, Halloran, John W.
• Primary Examiner(s): SANDERS, JAMES M
• Application Number:
  US12/435,776
• Publication Number:
  US 20100003619A1
• Time in Patent Office: 1,729 Days
• Field of Search: 425/174.4, 264/401, 264/405
• US Class Current: 425/174.4
• CPC Class Codes: B22C 9/02 Sand moulds or like moulds for shaped castings
• CPC Class Codes: B22C 9/24 for hollow articles
• CPC Class Codes: B29C 64/135 the energy source being concentrated, e.g. scanning lasers or focused light sources
• CPC Class Codes: B33Y 10/00 Processes of additive manufacturing
• CPC Class Codes: B33Y 30/00 Apparatus for additive manufacturing; Details thereof or accessories therefor
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• CPC Class Codes: G03B 27/42 for automatic sequential copying of the same original G03B27/34, G03B27/53 take precedence
• CPC Class Codes: G03F 7/2057 using an addressed light valve, e.g. a liquid crystal device
• CPC Class Codes: G03F 7/70291 Addressable masks, e.g. spatial light modulators [SLMs], digital micro-mirror devices [DMDs] or liquid crystal display [LCD] patterning devices
• CPC Class Codes: G03F 7/70416 2.5D lithography

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.

Claims

1. A system for fabricating a three-dimensional object, the system comprising:

an optical imaging system providing a light source;

a liquid photosensitive medium adapted to change states upon exposure to a portion of the light from the optical imaging system;

a control system for controlling movement of the optical imaging system with one micron positioning accuracy, wherein the optical imaging system moves continuously above the photosensitive medium to prevent flow related disturbances in the photosensitive medium; and

the optical imaging system comprising;

a reflector receiving a portion of the light;

an optical lens system comprising a lens that receives a portion of the reflected light;

a spatial light modulator for receiving the reflected light from the optical lens system;

and a projection lens for focusing the light received from the spatial light modulator onto a surface of the photosensitive medium.

2. The system of claim 1, the optical imaging system comprising a maskless light system for providing the light source and comprising a spatial light modulator scanning a portion of the medium.

3. The system of claim 1, the photosensitive medium comprising a photopolymer.

4. The system of claim 1, the control system receiving a computer aided design drawing.

5. The system of claim 1, the optical imaging system projecting a two-dimensional image comprising a cross-section of a three-dimensional object to be formed, the two-dimensional image received from the control system, onto a surface of the medium.

6. The system of claim 5, the projected two-dimensional image is a dynamic image that continuously changes as the optical imaging system scans over the medium.

7. The system of claim 1, further comprising a container for housing the photosensitive medium, the container comprising a lower platform adapted to move downwardly for lowering away from the optical imaging system, and wherein the container includes an inlet for introducing more of the photosensitive medium therein.

8. The system of claim 1, the light continuously changes as the optical light system moves over the surface of the photosensitive medium.

9. The system of claim 1, further comprising a recoating system for rapidly coating a uniform thickness of the photosensitive medium.