3D printer for photopolymerizing a photosensitive plastic resin using a lighting pattern

Patent metadata

Field	Value
Publication number	US-11833743-B2
Application number	US-202017608397-A
Country	US
Kind code	B2
Filing date	Apr 30, 2020
Priority date	May 3, 2019
Publication date	Dec 5, 2023
Grant date	Dec 5, 2023

Abstract

A 3D printing apparatus includes a synthetic resin bath for a photosensitive synthetic resin and a lifting apparatus. The photosensitive synthetic resin at the lifting apparatus is polymerizable by light of a specified wavelength. The 3D printing apparatus further includes a carrier medium having a coupling-in region and a coupling-out region, and an illumination apparatus to emit light onto the coupling-in region. The coupling-in region includes a coupling-in deflection structure to couple light of the specified wavelength incident on the coupling-in deflection structure from the illumination apparatus, into the carrier medium in a direction of the coupling-out region, and the coupling-out region is disposed below the synthetic resin bath and includes a coupling-out deflection structure configured to couple the light of the specified wavelength that is incident on the coupling-out deflection structure, as an exposure pattern, out of the carrier medium onto the photosensitive synthetic resin.

First claim

The invention claimed is:

1. A 3D printing apparatus for photopolymerizing a photosensitive synthetic resin using an exposure pattern, the 3D printing apparatus comprising:
a synthetic resin bath in which the photosensitive synthetic resin is provided;
a lifting apparatus, wherein the photosensitive synthetic resin at the lifting apparatus is polymerizable by light of a specified wavelength as a hardened body, the lifting apparatus being configured to move the hardened body up and out of the synthetic resin bath to change an exposure plane for the photosensitive synthetic resin with respect to the hardened body;
a carrier medium configured to transmit as a light guide light by internal reflection, and including a coupling-in region and a coupling-out region which are disposed in different sections of the carrier medium; and
an illumination apparatus configured to emit the light onto the coupling-in region,
wherein
the coupling-in region includes a coupling-in deflection structure configured to couple light of the specified wavelength that is incident on the coupling-in deflection structure from the illumination apparatus, into the carrier medium in a direction of the coupling-out region, and
the coupling-out region is disposed below the synthetic resin bath and includes a coupling-out deflection structure configured to couple the light of the specified wavelength that is incident on the coupling-out deflection structure, as an exposure pattern, out of the carrier medium onto the photosensitive synthetic resin of the synthetic resin bath to photopolymerize the photosensitive synthetic resin.

2. The 3D printing apparatus as claimed in claim 1 wherein the coupling-in deflection structure and the coupling-out deflection structure are each configured as a holographic element including at least one optical grating.

3. The 3D printing apparatus as claimed in claim 2 , wherein
the at least one optical grating of the coupling-in deflection structure includes a volume holographic grating or a surface holographic grating, and
the at least one optical grating of the coupling-out deflection structure includes the volume holographic grating or the surface holographic grating.

4. The 3D printing apparatus as claimed in claim 2 , wherein
the illumination apparatus includes an infrared emitter, and the coupling-in deflection structure and the coupling-out deflection structure are each configured as a multiplex diffraction structure, which is configured to diffract light of at least the specified wavelength and light of the infrared emitter at a predetermined angle.

5. The 3D printing apparatus as claimed in claim 1 , wherein the coupling-in region and the coupling-out region are formed as one piece with the carrier medium, or
the carrier medium is formed as a separate element from the coupling-in region and the coupling-out region.

6. The 3D printing apparatus as claimed in claim 1 , wherein
the coupling-in region is smaller than the coupling-out region,
the coupling-in deflection structure includes a scattering grating structure configured to deflect light beams of the light that is incident on the coupling-in deflection structure to different extents based on a site of incidence, so that the coupling-in deflection structure fans out the light beams onto the coupling-out deflection structure, and
the coupling-out deflection structure includes a focusing grating structure configured to deflect light beams of the light to different extents based on the site of incidence and to parallelize or focus the light beams onto the photosensitive synthetic resin of the synthetic resin bath to couple the light beams out of the carrier medium.

7. The 3D printing apparatus as claimed in claim 1 , wherein
the illumination apparatus includes a projector with an interchangeable photomask, and
the projector is configured to establish an emission characteristic forming the exposure pattern for exposing the photosensitive synthetic resin.

8. The 3D printing apparatus as claimed in claim 1 , wherein
the illumination apparatus includes a focus device configured to emit focused light beams onto the coupling-in region, and
the focused light beams, after they have been transmitted through the carrier medium to the coupling-out region and after they have emerged from the coupling-out region, intersect in a focal plane in the synthetic resin bath.

9. The 3D printing apparatus as claimed in claim 1 , wherein
the illumination apparatus includes a scanning apparatus with a light source, and
the scanning apparatus is configured to polymerize the photosensitive synthetic resin by scanning the coupling-in region based on a scanning position of the scanning apparatus.

10. The 3D printing apparatus as claimed in claim 1 , further comprising:
a camera apparatus disposed adjacent to the illumination apparatus and configured to record an image of a polymerization state of the photosensitive synthetic resin to monitor photopolymerization by recording light of the image of the polymerization state of the photosensitive synthetic resin which is reflected back from the synthetic resin bath through the coupling-out region, the carrier medium, and the coupling-in region, and into the camera apparatus.

11. The 3D printing apparatus as claimed in claim 1 , wherein the carrier medium forms a bottom of the synthetic resin bath.

12. The 3D printing apparatus as claimed in claim 1 , wherein
the carrier medium forms a bottom of the synthetic resin bath,
the carrier medium is transparent, and
an area of the coupling-in region is smaller than an area of the coupling-out region.

Assignees

• Audi Ag

Inventors

• Klug Markus
• Moll Tobias
• Scheuchenpflug Johannes

Classifications

• B29C64/129 Primary

  characterised by the energy source therefor, e.g. by global irradiation combined with a mask · CPC title

• B29C64/245

  Platforms or substrates (support structures intended to be sacrificed after manufacture B29C64/40) · CPC title

• B29C64/264

  Arrangements for irradiation · CPC title

• B33Y30/00

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

• B33Y10/00

  Processes of additive manufacturing · CPC title