Dual wavelength negative imaging DLP-SLA system and method

1. A method for forming a three dimensional (3D) component from a photopolymer resin, the method comprising:

generating a first optical beam at a first wavelength using a first light source, the first optical beam causing polymerization of a photopolymerizable resist;

generating a second optical beam at a second wavelength using a second light source, the second wavelength being different from the first wavelength, and which inhibits polymerization of the photopolymerizable resist; and

using a digital micromirror device (DMD) having a plurality of independently tiltable micromirrors to receive the first and second optical beams and to generate therefrom corresponding separate first and second light patterns, respectively, where:

further positioning the first and second light sources to be offset from one another by an identical angle, in degrees, relative to an axis extending normal to a tilt axis of each of the micromirrors of the DMD, to project the first and second beams at the DMD at two different angles relative to the axis;

the DMD resolving the first and second light patterns into a single composite, interleaved image;

the first light pattern transmitted from the DMD forms a first image on the photopolymerizable resist to cause polymerization of a first portion of the photopolymerizable resist, while

the second light pattern transmitted from the DMD forms a second image on the photopolymerizable resist and inhibits polymerization of a second portion of the photopolymerizable resist;

wherein the micromirrors of the DMD further being controlled by the electronic controller to simultaneously position each one of said micromirrors 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 to initiate photopolymerization of the first portion of the photopolymerizable resist, and when any selected one of the micromirrors is positioned in the second position of tilt, the selected micromirror simultaneously receives and reflects only the second beam toward the photopolymerizable resist to inhibit photopolymerization of the second portion of the photopolymerizable resist.

2. The method of claim 1 , wherein the first and second wavelengths produce the first and second images, respectively, which are negatives of one another.

3. The method of claim 1 , where a wavelength of the second optical beam is shorter than a wavelength of the first optical beam.

4. The method of claim 1 , wherein generating the first optical beam comprises generating the first optical beam using a first LED or a first laser.

5. The method of claim 1 , wherein generating the second optical beam comprises generating the second optical beam using at least one of a second LED or a second laser.

6. The method of claim 1 , further comprising using a first alignment and conditioning optics subsystem for receiving and conditioning the first optical beam.

7. The method of claim 6 , further comprising using a second alignment and conditioning optics subsystem for receiving and conditioning the second optical beam.

8. The method of claim 7 , further comprising positioning the first and second alignment and conditioning optics subsystems to be offset by an identical but opposite angle, in degrees, relative to an axis extending normal to a tilt axis of the DMD.

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

10. The method of claim 1 , further comprising using an electronic controller to control power levels of the first and second light sources.

11. A method for forming a three dimensional (3D) component from a photopolymer resin, the method comprising:

using a first light source to generate a first optical beam at a first wavelength, the first optical beam causing polymerization of a photopolymerizable resist;

using a second light source to generate a second optical beam at a second wavelength, different from the first wavelength, which inhibits polymerization of the photopolymerizable resist; and

using a tilting micromirror device having first and second subpluralities of micromirrors to receive the first and second optical beams, respectively, and to generate therefrom corresponding separate first and second light patterns, respectively, where:

the first light pattern forms a first image on the photopolymerizable resist to cause polymerization of a first portion of the photopolymerizable resist, while

the second light pattern forms a second image on the photopolymerizable resist and inhibits polymerization of a second portion of the photopolymerizable resist;

the first and second light sources further configured to be offset on opposite sides from an axis extending normal to a surface of the tilting micromirror device by identical angles relative to the axis;

controlling tilting of the first subplurality of micromirrors from an OFF state to an ON state to cause only the first subplurality of micromirrors to illuminate the photopolymerizable resist with the first optical beam, to thus cause photopolymerization of a first portion of the photopolymerizable resist; and

wherein remaining ones of the micromirrors not in the ON state form the second subplurality of micromirrors, and the second subplurality of micromirrors is in the OFF state, causing only the second plurality of mirrors to reflect the second optical beam toward the photopolymerizable resist, to inhibit photopolymerization of a second portion of the photopolymerizable resist.

12. The method of claim 11 , wherein the first and second wavelengths produce the first and second images as negatives of one another.

13. The method of claim 11 , where a wavelength of the second optical beam is shorter than a wavelength of the first optical beam.

14. The method of claim 11 , wherein:

using a first light source comprises using at least one of a first LED or a first laser; and

using a second light source comprises using at least one of a second LED or a second laser.

15. A method for forming a three dimensional (3D) component from a photopolymer resin, the method comprising:

using a first light source to generate a first optical beam at a first wavelength, the first optical beam causing polymerization of a photopolymerizable resist;

using a second light source to generate a second optical beam at a second wavelength, shorter than the first wavelength, which inhibits polymerization of the photopolymerizable resist; and

using a digital micromirror device (DMD) having a plurality of micromirrors to receive the first and second optical beams, respectively, and to generate therefrom corresponding separate first and second light patterns, respectively, where:

the first light pattern forms a first image on the photopolymerizable resist to cause polymerization of a first portion of the photopolymerizable resist, while

the second light pattern forms a second image on the photopolymerizable resist and inhibits polymerization of a second portion of the photopolymerizable resist, the second image being a negative of the first image;

the first and second light sources configured to be offset on opposite sides from an axis extending normal to a surface of the DMD, while simultaneously illuminating the DMD with the first and second optical beams; and

controlling tilting of a first subplurality of the plurality of micromirrors to cause only the first subplurality of micromirrors to reflect the first optical beam toward the photopolymerizable resist, to thus cause photopolymerization of a first portion of the photopolymerizable resist, while causing the first subplurality of micromirrors to reflect the second optical beam away from the photopolymerizable resist; and

simultaneously controlling tilting of a second subplurality of micromirrors of the plurality of micromirrors to reflect only the second optical beam toward the photopolymerizable resist, to inhibit photopolymerization of a second portion of the photopolymerizable resist, while the second subplurality of micromirrors reflect the first optical beam away from the photopolymerizable resist.

16. The method of claim 15 , wherein:

using a first light source comprises using at least one of a first LED or a first laser; and

using a second light source comprises using at least one of a second LED or a second laser.