Building platform for building up a workpiece in layers or continuously

Patent metadata

Field	Value
Publication number	US-11571850-B2
Application number	US-202117233798-A
Country	US
Kind code	B2
Filing date	Apr 19, 2021
Priority date	Apr 22, 2020
Publication date	Feb 7, 2023
Grant date	Feb 7, 2023

Abstract

The present invention relates to a building platform (100) for building up a workpiece (200) in layers or continuously by stereolithography, comprising: a rear illumination device (101-1) for illuminating a layer (103-n) from a rear side; a photosensor (105) for detecting a light intensity of a light from a front illumination device (101-2) through the layer (103-n) and/or a material and/or a deflecting mirror; and a control device (107) for activating the rear illumination device (101-1) when the detected light intensity of the front illumination device (101-2) is above a predetermined threshold.

First claim

The invention claimed is:

1. A stereolithography method for building up a workpiece ( 200 ) in layers or continuously using a stereolithography printer including a building platform ( 100 ), comprising the steps of:
illuminating (S 101 ) a layer ( 103 - n ) from a front side using a front illumination device ( 101 - 2 );
detecting (S 102 ) a light intensity of a light from the front illumination device ( 101 - 2 ) through the layer ( 103 - n ) and/or a material and/or via a deflecting mirror using a photosensor ( 105 ); and
activating (S 103 ) a rear illumination device ( 101 - 1 ) using a printer-independent control device ( 107 ) if the detected light intensity of the front illumination device ( 101 - 2 ) is above a predetermined threshold.

2. The method according to claim 1 , wherein the rear illumination device ( 101 - 1 ) is activated for a predetermined number of layers and/or using an adjusted illumination duration for each layer.

3. The method according to claim 1 , wherein a height of the building platform ( 100 ) is taken into account for the building process to determine the start position of the building platform ( 100 ) and to set a predetermined layer thickness of the layer ( 103 - n ).

4. A stereolithography method for building up a workpiece ( 200 ) in layers or continuously using a stereolithography printer including a building platform ( 100 ), comprising the steps of:
detecting a layer using a detection device ( 105 ); and
activating a rear illumination device ( 101 - 1 ) using a printer-independent control device ( 107 ) when the layer is detected.

5. The method according to claim 4 , wherein the rear illumination device ( 101 - 1 ) is activated for a predetermined number of layers and/or using an adjusted illumination duration for each layer.

6. The method according to claim 4 , wherein a height of the building platform ( 100 ) is taken into account for the building process to determine the start position of the building platform ( 100 ) and to set a predetermined layer thickness of the layer ( 103 - n ).

7. A building platform ( 100 ) for building up a workpiece ( 200 ) in layers or continuously by a stereolithography printer, comprising:
a rear illumination device ( 101 - 1 ) for illuminating a layer ( 103 - n ) from a rear side;
a photosensor ( 105 ) for detecting a light intensity of a light from a front illumination device ( 101 - 2 ) through the layer ( 103 - n ) and/or through a material and/or from deflection by a deflecting mirror; and
a printer-independent control device ( 107 ) for activating the rear illumination device ( 101 - 1 ) when the detected light intensity of the front illumination device ( 101 - 2 ) is above a predetermined threshold.

8. The building platform ( 100 ) according to claim 7 , wherein the rear illumination device ( 101 - 1 ) is formed by an LED matrix.

9. The building platform ( 100 ) according to claim 7 , wherein the light intensity or illumination time of the rear illumination device ( 101 - 1 ) can be set using a potentiometer or by an internal control system, and/or the number of rear-illuminated layers ( 103 - n ) can be controlled using a counter.

10. The building platform ( 100 ) according to claim 7 , wherein the building platform ( 100 ) comprises an electrical energy store ( 115 ) for storing energy for the rear illumination device ( 101 - 1 ).

11. The building platform ( 100 ) according to claim 10 , wherein the energy store is a rechargeable battery, replaceable battery or both rechargeable and replaceable.

12. The building platform according to claim 7 , wherein the photosensor ( 105 ) is a photodiode which is tuned to a wavelength range of the front illumination.

13. The building platform ( 100 ) according to claim 12 , wherein the photodiode is sensitive in the wavelength range of the front illumination device in the UVA range or in the blue light range.

14. The building platform ( 100 ) according to claim 7 , wherein the predetermined threshold for activating the rear illumination can be set by a user.

15. The building platform ( 100 ) according to claim 7 , wherein the building platform ( 100 ) with the rear illumination device ( 101 - 1 ) can be inserted modularly into a stereolithography device ( 300 ) or the rear illumination device ( 101 - 1 ) can be modularly placed on or slid onto the building platform ( 100 ).

16. A stereolithography device ( 300 ) comprising the building platform according to claim 7 .

17. The stereolithography device ( 300 ) according to claim 16 , characterised in that the stereolithography device ( 300 ) is formed so that part of the light of the front illumination device, which is used for illuminating the first layer, is deflected onto the photosensor, and the rear illumination device is thus activated.

18. A building platform ( 100 ) for building up a workpiece ( 200 ) in layers or continuously by a stereolithography printer, comprising:
a rear illumination device ( 101 - 1 ) for illuminating a layer ( 103 - n ) from a rear side;
a detection device ( 105 ) for detecting the layer ( 103 - 1 ); and
a printer-independent control device ( 107 ) for activating the rear illumination device ( 101 - 1 ) when the layer ( 103 - 1 ) is detected.

19. A stereolithography device ( 300 ) comprising the building platform according to claim 18 .

Assignees

• Ivoclar Vivadent Ag

Inventors

• John Hendrik

Classifications

• B29C64/245 Primary

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

• B33Y30/00

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

• B29C64/264

  Arrangements for irradiation · CPC title

• B33Y10/00

  Processes of additive manufacturing · CPC title

• B29C64/393

  for controlling or regulating additive manufacturing processes · CPC title