System for online monitoring powder-based 3d printing processes and method thereof

Patent metadata

Field	Value
Publication number	US-2016176114-A1
Application number	US-201514803679-A
Country	US
Kind code	A1
Filing date	Jul 20, 2015
Priority date	Dec 17, 2014
Publication date	Jun 23, 2016
Grant date	—

Abstract

A system for online monitoring powder-based 3D printing processes and method thereof are disclosed. A uniform light source having a single wavelength provided by the system is irradiated onto the powder layer before and after applied with glue. Intensities of such reflected images are obtained and subtracted from each other in an image process procedure. A difference obtained through the subtraction is compared with an original 3D model in a computer. If any defect is found such as being larger than a threshold value, the powder-based 3D printing processes will be terminated. Therefore, the technical effects of online printing processes monitoring, time saving and printing resources saving will be achieved.

First claim

What is claimed is:

1 . A method for online monitoring powder-based 3D printing processes, being an online monitoring performed when a powder bed is printed layer by layer based on a 3D model on a computer, the method at least comprising the following steps:
(a) when the computer replies that a paving of a powder layer of the powder bed is completed, the powder bed irradiated by a uniform light having a single wavelength to acquire a first reflected image and corresponding first light intensity information; (b) after the computer replies that the powder layer of the powder bed is applied with glue, the powder bed again irradiated by the light to acquire a second reflected image and corresponding second light intensity information; (c) performing an image processing to the first and second light intensity information to obtain a contour of pattern; (d) comparing the contour of pattern with the 3D model and determine whether a contour defect is caused; (e) when the contour defect is not caused, the computer informed for printing; (f) when the computer replies that the printing is not yet completed and the paving of a new powder layer of the powder bed is completed, step (a) to step (f) repeated; and (g) when the computer replies that the printing is completed, the online monitoring terminated.

2 . The method for online monitoring powder-based 3D printing processes of claim 1 , further comprising step (h), when the contour defect is caused, the computer is informed to stop printing and terminate the online monitoring.

3 . The method for online monitoring powder-based 3D printing processes of claim 1 , further comprising step (i), when the contour defect is caused, it is further determined whether the contour defect exceeds a preset ratio.

4 . The method for online monitoring powder-based 3D printing processes of claim 3 , wherein the step (i) further comprises the following steps:
(i1) when the contour defect does not exceed the ratio, the computer is informed for printing and goes to the step (f); and (i2) when the contour defect exceeds the ratio, the computer is informed to stop printing and terminate the online monitoring.

5 . The method for online monitoring powder-based 3D printing processes of claim 3 , wherein the ratio refers to a ratio of area of the contour of pattern compared to a protrusion and/or a recession of the contour of 3D model.

6 . The method for online monitoring powder-based 3D printing processes of claim 1 , wherein the image processing generates the contour of pattern through a light intensity difference between both the first light intensity information corresponding to the first reflected image and the second light intensity information corresponding to the second reflected image after subtraction.

7 . The method for online monitoring powder-based 3D printing processes of claim 1 , wherein the light is the LED with a wavelength ranged from 405 nm to 660 nm.

8 . The method for online monitoring powder-based 3D printing processes of claim 1 , wherein the light is ultraviolet light.

9 . A system for online monitoring powder-based 3D printing processes, performing an online monitoring when a powder bed is printed layer by layer based on a 3D model on a computer, the system at least comprising:
a light supplying module, comprising a light controller to switch a light source, when the computer replies that a paving of a powder layer of the powder bed is completed, at least one light source actuated by the light controller to irradiate a uniform light having a single wavelength on the powder bed, and after the computer replies that the powder layer of the powder bed is applied with glue, at least one light source described actuated by the light controller to irradiate the light on the powder bed again; an image acquiring module, used for controlling an image acquiring device, when the computer replies that the paving of the powder layer of the powder bed is completed and the light supplying module is actuated, a first reflected image is acquired, and after the computer replies that the powder layer of the powder bed is applied with glue and the light supplying module is actuated, a second reflected image is acquired; a contour determining module, used for obtaining the first reflected image and the second reflected image from the image acquiring module, getting first light intensity information and second light intensity information respectively to perform an image processing in order to obtain a contour of pattern, and performing image comparison between the contour of pattern and the 3D model to determine whether a contour defect is caused; and a printer monitoring module, used for informing the computer to print when the contour determining module determines that the contour defect is not caused, and terminating the online monitoring when the computer replies that the printing is completed.

10 . The system for online monitoring powder-based 3D printing processes of claim 9 , wherein the printer monitoring module further comprises, when the contour defect is caused, the computer is informed to stop printing and terminate the online monitoring.

11 . The system for online monitoring powder-based 3D printing processes of claim 9 , wherein the contour determining module further comprises, when the contour defect is caused, the contour determining module further determines whether the contour defect exceeds a preset ratio.

12 . The system for online monitoring powder-based 3D printing processes of claim 9 , wherein the printer monitoring module further comprises:
when the contour defect does not exceed the ratio, the computer is informed for printing; and when the contour defect exceeds the ratio, the computer is informed to stop printing and terminate the online monitoring.

13 . The system for online monitoring powder-based 3D printing processes of claim 11 , wherein the ratio refers to a ratio of area of the contour of pattern compared to a protrusion and/or a recession of the contour of 3D model.

14 . The system for online monitoring powder-based 3D printing processes of claim 9 , wherein the image processing generates the contour of pattern through a light intensity difference between both the first light intensity information corresponding to the first reflected image and the second light intensity information corresponding to the second reflected image after subtraction.

15 . The system for online monitoring powder-based 3D printing processes of claim 9 , wherein the light is the LED with a wavelength ranged from 405 nm to 660 nm.

16 . The system for online monitoring powder-based 3D printing processes of claim 9 , wherein the light is ultraviolet light.

Assignees

• Nat Applied Res Laboratories

Inventors

• Tsai Hsin-Yi
• Hung Min-Wei
• Huang Kuo-Cheng
• Ou Keng-Liang
• Yang Ching-Ching

Classifications

• B29C64/393 Primary

  for controlling or regulating additive manufacturing processes · CPC title

• B33Y50/02 Primary

  for controlling or regulating additive manufacturing processes · CPC title

• B29C67/0088 Primary

  Operations & Transport · mapped topic

• G05B19/4099

  Surface or curve machining, making three-dimensional [3D] objects, e.g. desktop manufacturing · CPC title

• G05B2219/35134

  3-D cad-cam · CPC title