Detection of 3d printing failure using imaging

Abstract

Apparatuses and methods for detecting failures in a photoreactive 3D printing system include a light-emitting device configured to emit light into and along a plane of a membrane or of a substrate below the membrane. The membrane is a bottom surface of a resin tub. The light has a wavelength that is different from a photopolymerization wavelength of resin in the resin tub. The membrane or substrate is transparent to the wavelength of the light and to the photopolymerization wavelength. An imaging device is oriented to capture an image of the light emitted from the membrane or the substrate.

What is claimed is: 
     
         1 . A failure detection apparatus for a photoreactive 3D printing system, the apparatus comprising:
 a light-emitting device configured to emit light into and along a plane of a membrane, the membrane being a bottom surface of a resin tub, wherein the light has a wavelength that is different from a photopolymerization wavelength of resin in the resin tub, and wherein the membrane is transparent to the wavelength of the light and to the photopolymerization wavelength; and   an imaging device oriented to capture an image of light emitted from the membrane.   
     
     
         2 . The apparatus of  claim 1 , further comprising a transparent sheet adjacent to the bottom surface of the resin tub, the transparent sheet supporting the membrane. 
     
     
         3 . The apparatus of  claim 1 , wherein the light-emitting device is an infrared (IR) light source and the imaging device is an infrared camera. 
     
     
         4 . The apparatus of  claim 1 , further comprising a mirror, wherein:
 the mirror is reflective for the wavelength of the light from the light-emitting device and transmissive for the photopolymerization wavelength;   the mirror is angled relative to the membrane and reflects the image to the imaging device; and   the imaging device is off-axis from a central axis perpendicular to the plane of the membrane.   
     
     
         5 . The apparatus of  claim 1 , wherein the membrane comprises a plurality of layers, the layers having different indices of refraction from each other. 
     
     
         6 . The apparatus of  claim 5 , wherein a middle layer in the plurality of layers has an index of refraction that is less than the indices of refraction of an upper layer and a lower layer surrounding the middle layer. 
     
     
         7 . A failure detection apparatus for a photoreactive 3D printing system, the apparatus comprising:
 a substrate below a membrane of a resin tub, wherein the membrane is a bottom surface of the resin tub;   a light-emitting device configured to emit light into and along a plane of the substrate, wherein the light has a wavelength that is different from a photopolymerization wavelength of resin in the resin tub, and wherein the substrate is transparent to the wavelength of the light and to the photopolymerization wavelength; and   an imaging device oriented to capture an image of light emitted from the substrate.   
     
     
         8 . The apparatus of  claim 7 , further comprising a substrate holder, wherein:
 the light-emitting device is coupled to a surface of the substrate holder; and   an edge of the substrate is supported by the substrate holder and placed adjacent to the light-emitting device.   
     
     
         9 . The apparatus of  claim 7 , wherein the light-emitting device is an infrared (IR) light source and the imaging device is an infrared camera. 
     
     
         10 . The apparatus of  claim 7 , wherein the substrate is a glass sheet having a sheet plane with a size equal to or greater than the plane of the membrane. 
     
     
         11 . The apparatus of  claim 7 , further comprising a mirror, wherein:
 the mirror is reflective for the wavelength of the light of the light-emitting device and transmissive for the photopolymerization wavelength;   the mirror is angled relative to the substrate and reflects the image to the imaging device; and   the imaging device is off-axis from a central axis perpendicular to the plane of the substrate.   
     
     
         12 . The apparatus of  claim 7 , further comprising a second light-emitting device configured to emit light of a second wavelength into and along a plane of the membrane, the second wavelength being different from the wavelength of the light emitted into the substrate;
 wherein the imaging device is further configured to capture a second image of the light of the second wavelength emitted from the membrane.   
     
     
         13 . The apparatus of  claim 7 , wherein the substrate comprises a plurality of layers, the layers having different indices of refraction from each other. 
     
     
         14 . The apparatus of  claim 13 , wherein a middle layer in the plurality of layers has an index of refraction that is less than the indices of refraction of an upper layer and a lower layer surrounding the middle layer. 
     
     
         15 . A method for detecting failures in a photoreactive 3D printing system, the method comprising:
 emitting light of a first wavelength into and along a plane of a substrate using a light-emitting device, wherein the substrate is mounted onto or below a resin tub, wherein the first wavelength is different from a photopolymerization wavelength of resin in the resin tub, and wherein the substrate is transparent to the light of the first wavelength and to light of the photopolymerization wavelength; and   capturing an image of light emitted from the substrate using an imaging device.   
     
     
         16 . The method of  claim 15 , further comprising:
 detecting, using a detection system that is in communication with the imaging device, a spatial disruption or a temporal disruption in the image.   
     
     
         17 . The method of  claim 16 , further comprising sending an alert when the spatial disruption or the temporal disruption is detected. 
     
     
         18 . The method of  claim 16 , further comprising capturing, using the imaging device, a plurality of images at a plurality of time points; and
 wherein the detecting of the temporal disruption comprises identifying a change between the plurality of images.   
     
     
         19 . The method of  claim 15 , further comprising providing a mirror, wherein:
 the mirror is reflective for the first wavelength of the light from the light-emitting device and transmissive for the photopolymerization wavelength;   the mirror is angled relative to the substrate and reflects the image to the imaging device; and   the imaging device is off-axis from a central axis perpendicular to the plane of the substrate.   
     
     
         20 . The method of  claim 15 , wherein:
 the substrate is mounted below a membrane of the resin tub, the membrane serving as a bottom surface of the resin tub; and   the method further comprises emitting light of a second wavelength into and along a plane of the membrane using a second light-emitting device, the second wavelength being different from the first wavelength.