Enhanced three dimensional printing of vertical edges

Abstract

Techniques and systems for enhancing vertical edges during photopolymer-based three-dimensional (3D) printing are described. A described technique includes accessing an original image corresponding to a slice of a 3D model prepared for printing on a 3D printer; accessing a pixel reduction factor that is associated with an increased exposure duration parameter; classifying pixels of the original image; reducing intensity levels of the interior pixels by the pixel reduction factor so that corresponding printing areas receive first curing doses under the increased exposure duration parameter and the reduced intensity levels that are comparable to doses received under an unmodified exposure duration parameter and unreduced intensity levels; maintaining intensity levels of the exterior pixels so that corresponding printing areas receive second curing doses under the increased exposure duration parameter that are greater than doses associated with the unmodified exposure duration parameter; and outputting a resulting modified image for 3D printing.

1 .- 19 . (canceled) 
     
     
         20 . A method for processing a three-dimensional (3D) object for printing by a 3D printer, comprising:
 (a) obtaining, by a computer processor, a digital image corresponding to at least a portion of said 3D object;   (b) identifying, by said computer processor, at least one interior pixel of said digital image and at least one exterior pixel of said digital image;   (c) changing, by said computer processor, a light intensity level of said at least one interior pixel and an additional light intensity level of said at least one exterior pixel relative to one another, to generate a light intensity level profile of said digital image, wherein said light intensity profile is usable by said 3D printer to print said at least said portion of said 3D object.   
     
     
         21 . The method of  claim 20 , wherein, in (c), one of said light intensity level and said additional light intensity level is reduced, while the other of said light intensity level and said additional light intensity level remains substantially unchanged. 
     
     
         22 . The method of  claim 20 , further comprising assigning increased duration of exposure of (i) said at least one interior pixel to light at said light intensity level that is changed or (ii) said at least one exterior pixel to light at said additional light intensity level that is changed. 
     
     
         23 . The method of  claim 22 , comprising assigning increased duration of exposure of (i) said at least one interior pixel to light at said light intensity level that is changed and (ii) said at least one exterior pixel to light at said additional light intensity level that is changed. 
     
     
         24 . The method of  claim 22 , wherein said light intensity level and said additional light intensity level are changed based at least in part on said increased duration of exposure. 
     
     
         25 . The method of  claim 20 , wherein said light intensity level and said additional light intensity level are changed based on a nominal curing parameter of a resin that is usable for forming said at least said portion of said 3D object. 
     
     
         26 . The method of  claim 20 , wherein said light intensity level and said additional light intensity level are changed to enhance curing quality of said at least said portion of said 3D object. 
     
     
         27 . The method of  claim 20 , wherein said light intensity level and said additional light intensity level are changed to enhance curing quality at one or more edges of said at least said portion of said 3D object. 
     
     
         28 . The method of  claim 20 , wherein said identifying comprises classifying a target pixel as said at least one exterior pixel when one or more neighboring pixels of said target pixel has a black light intensity level. 
     
     
         29 . The method of  claim 20 , further comprising sending said light intensity level profile to said 3D printer to print said at least said portion of said 3D object. 
     
     
         30 . A system for processing a three-dimensional (3D) object for printing by a 3D printer, comprising:
 a computer processor in digital communication with a computer memory, wherein said computer processor is configured to:
 (a) obtain a digital image corresponding to at least a portion of said 3D object; 
 (b) identify at least one interior pixel of said digital image and at least one exterior pixel of said digital image; 
 (c) change a light intensity level of said at least one interior pixel and an additional light intensity level of said at least one exterior pixel relative to one another, to generate a light intensity level profile of said digital image, wherein said light intensity profile is usable by said 3D printer to print said at least said portion of said 3D object. 
   
     
     
         31 . The system of  claim 30 , wherein, in (c), one of said light intensity level and said additional light intensity level is reduced, while the other of said light intensity level and said additional light intensity level remains substantially unchanged. 
     
     
         32 . The system of  claim 30 , wherein said computer processor is further configured to increase duration of exposure of (i) said at least one interior pixel to light at said light intensity level that is changed or (ii) said at least one exterior pixel to light at said additional light intensity level that is changed. 
     
     
         33 . The system of  claim 32 , wherein said computer processor is configured to increase duration of exposure of (i) said at least one interior pixel to light at said light intensity level that is changed and (ii) said at least one exterior pixel to light at said additional light intensity level that is changed. 
     
     
         34 . The system of  claim 32 , wherein said light intensity level and said additional light intensity level are changed based at least in part on said increased duration of exposure. 
     
     
         35 . The system of  claim 30 , wherein said light intensity level and said additional light intensity level are changed based on a nominal curing parameter of a resin that is usable for forming said at least said portion of said 3D object. 
     
     
         36 . The system of  claim 30 , wherein said light intensity level and said additional light intensity level are changed to enhance curing quality of said at least said portion of said 3D object. 
     
     
         37 . The system of  claim 30 , wherein said light intensity level and said additional light intensity level are changed to enhance curing quality at one or more edges of said at least said portion of said 3D object. 
     
     
         38 . The system of  claim 30 , wherein said identifying in (b) comprises classifying a target pixel as said at least one exterior pixel when one or more neighboring pixels of said target pixel has a black light intensity level. 
     
     
         39 . The system of  claim 30 , wherein said computer processor is further configured to send said light intensity level profile to said 3D printer to print said at least said portion of said 3D object. 
     
     
         19 . The three-dimensional printer of claim  14 , wherein classifying the pixels comprises:
 accessing neighboring pixels of a target pixel of the original image, the target pixel having an intensity level greater than a black intensity level;   classifying the target pixel as an exterior pixel if one or more of the neighboring pixels have the black intensity level; and   classifying the target pixel as an interior pixel if all of the neighboring pixels have an intensity level greater than the black intensity level.