Dual wavelength negative imaging DLP-SLA system

Patent metadata

Field	Value
Publication number	US-11130288-B2
Application number	US-201816020529-A
Country	US
Kind code	B2
Filing date	Jun 27, 2018
Priority date	Jun 27, 2018
Publication date	Sep 28, 2021
Grant date	Sep 28, 2021

Abstract

The present disclosure relates to a digital light projector (DLP) system which has first and second light sources. The first optical source may generate a first beam at a first wavelength which causes polymerization of a photopolymerizable resist. The second optical source may generate a second beam at a second wavelength different from the first wavelength, and where the second beam inhibits polymerization of the photopolymerizable resist. A digital micromirror device (DMD) is included which has a plurality of micromirrors and is configured to be illuminated by the first and second beams and to generate a pattern on the micromirrors which has light from the first and second light wavelengths controlled by the micromirror position. The first light image causes polymerization of a first portion of the photopolymerizable resist, while the second image inhibits polymerization of a second portion of the photopolymerizable resist.

First claim

What is claimed is:

1. A digital light projector (DLP) system comprising:
a first light source for generating a first beam at a first wavelength, the first beam operable to cause polymerization of a photopolymerizable resist;
a second light source for generating a second beam at a second wavelength different from the first wavelength, and where the second beam is operative to inhibit polymerization of the photopolymerizable resist;
a digital micro mirror device (DMD) having a plurality of micromirrors configured to receive the first and second beams; and
an electronic controller configured to control the micromirrors of the DMD such that the DMD receives the first and second beams and simultaneously generates therefrom a first light pattern and a second light pattern, the first light pattern, when falling on the photopolymerizable resist, creating a first image made up of light of the first wavelength, and the second light pattern, when falling on the photopolymerizable resist, creating a second image made up of light of the second wavelength, the first and second images being interleaved with one another, and where the first wavelength light causes polymerization of a first portion of the photopolymerizable resist, while the second wavelength light inhibits polymerization of a second portion of the photopolymerizable resist; and
wherein the first and second light sources are positioned to be offset from one another by an identical angle, in degrees, relative to an axis extending normal to a tilt axis of a micromirror of the plurality of micromirrors of the DMD, to project the first and second beams at the DMD at two different angles relative to the axis; and
wherein the micromirrors of the DMD are controlled by the electronic controller to simultaneously position each micromirror in either a first position of tilt or a second position of tilt, and when any selected one of the micromirrors is positioned in the first position of tilt, the selected one of the micromirrors receives and reflects only the first beam toward the photopolymerizable resist, and when any selected one of the micromirrors is positioned in the second position of tilt, the selected one of the micromirrors simultaneously receives and reflects only the second beam toward the photopolymerizable resist.

2. The system of claim 1 , where a wavelength of the second beam is shorter than a wavelength of the first beam.

3. The system of claim 1 , wherein the first light source comprises at least one of: a first LED or a first laser.

4. The system of claim 1 , wherein the second light source comprises at least one of: a second LED or a second laser.

5. The system of claim 1 , wherein the first image forms a negative of the second image, and vice versa.

6. The system of claim 1 , wherein:
when a micromirror of the DMD is in the first position of tilt, the first one of the first and second beams is reflected parallel to the axis extending normal to a chip face of a chip face surface of the DMD and used for initiating polymerization, while the second one of the first and second beams is reflected from the micromirror at an angle non-parallel to the axis extending normal to the DMD chip face surface and not used for polymerization, and is directed outside of a projection optics collection space; and
when the micromirror of the DMD is in the second position of tilt, the first beam is reflected at the angle non-parallel to the axis extending normal to the DMD chip face surface and is not able to be used for polymerization and is directed outside of a projection optics collection space, and the second beam is reflected parallel to the axis extending normal to the tilt axis and is used for inhibiting polymerization of the photopolymerizable resist.

7. The system of claim 1 , further comprising:
a first alignment and conditioning optics subsystem for receiving and conditioning the first beam; and
a second alignment and conditioning optics subsystem for receiving and conditioning the second beam.

8. The system of claim 7 , wherein:
the first and second alignment and conditioning optics subsystems are positioned to be offset by an identical but opposite angle, in degrees, relative to an axis extending normal to a tilt axis of one micromirror of the plurality of micromirrors of the DMD.

9. The system of claim 1 , further comprising a memory operably associated with the electronic controller and in communication with the electronic controller for storing at least one of information or data pertaining to manufacture of a part using the system.

10. The system of claim 1 , wherein the electronic controller is configured to control power levels of the first and second light sources.

11. A three dimensional (3D) printing system for forming a structure from a photopolymer resin, the system comprising:
a first light source for generating a first beam at one of a first wavelength or a first wavelength range, the first beam operable to cause polymerization of a photopolymerizable resist;
a second light source for generating a second beam at one of a second wavelength or a second wavelength range, different from the first wavelength or first wavelength range, and where the second beam is operative to inhibit polymerization of the photopolymerizable resist; and
a digital micro mirror device (DMD) having a plurality of micromirrors, each of the micromirrors being tiltable between first and second tilt positions, and each being configured to simultaneously be illuminated by the first and second beams;
an electronic controller configured to control the micromirrors of the DMD to cause the micromirrors to act then acting as switches between either beam for each said micromirror, the DMD, then when imaged by the first and second beams, creates first and second light patterns which form simultaneously created first and second images on the photopolymer resist, and which overlay the first and second images on one another, respectively, where light from the first light pattern is used to make up the first image using the first wavelength and causes polymerization of the photopolymerizable resist, while the light from the second light pattern is used to create the second image on the photopolymer resist and is made up of the second wavelength, and inhibits polymerization of the photopolymerizable resist, and where the first and second images created on the photopolymerizable resist using the first and second light patterns are negative images of one another which are interleaved with one another; and
wherein the first and second light sources are positioned to be offset from one another by an identical angle, in degrees, relative to an axis extending normal to a tilt axis of a micromirror of the plurality of micromirrors of the DMD, to project the first and second beams at the DMD at two different angles relative to the axis;
wherein the micromirrors of the DMD are controlled by the electronic controller to position each one of the plurality of micromirrors selectively in either a first position of tilt or a second position of tilt, and:
when a first subplurality of the micromirrors is selectively positioned in the first position of tilt, the first subplurality of micromirrors receives and reflects only the first beam toward the photopolymerizable resist while receiving and reflecting the second beam away from the photopolymerizable resist; and
when a second subplurality of the micromirrors is selectively, simultaneously positioned in the second position of tilt, the second subplurality of the micromirrors receives and reflects only the second beam toward the photopolymerizable resist.

12. The system of claim 11 , wherein the first and sec

Assignees

• L Livermore Nat Security Llc

Inventors

• Moran Bryan D

Classifications

• B29C64/277 Primary

  using multiple radiation means, e.g. micromirrors or multiple light-emitting diodes [LED] · CPC title

• B33Y30/00

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

• B29C64/268 Primary

  using laser beams; using electron beams [EB] · CPC title

• B33Y40/00

  Auxiliary operations or equipment, e.g. for material handling · CPC title

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title