Converting at least a portion of a 3-D object into a format suitable for printing

• US 10,452,055 B2
• Filed: 10/29/2014
• Issued: 10/22/2019
• Est. Priority Date: 10/29/2014
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Morovic, Peter, Morovic, Jan
• Primary Examiner(s): Pringle-Parker, Jason A
• Application Number:
  US15/517,370
• Publication Number:
  US 20170246812A1
• Time in Patent Office: 1,819 Days
• Field of Search: None
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/00 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: G05B 19/4099 Surface or curve machining, making 3D objects, e.g. desktop manufacturing
• CPC Class Codes: G05B 2219/49023 3-D printing, layer of powder, add drops of binder in layer, new powder
• CPC Class Codes: G06T 19/00 Manipulating 3D models or images for computer graphics
• CPC Class Codes: H04N 1/405 Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels
• CPC Class Codes: H04N 1/605 for controlling ink amount, strike-through, bleeding soakage or the like

Abstract

At least a portion of a 3-D object is converted into a format suitable for printing. A material volume coverage vector for each voxel of a 3-D bit map of a 3-D object is determined. The 3-D bit map comprises a plurality of voxels, each voxel located at a unique 3-D location. A rectangular cuboid comprising an M×N×L array of voxel locations enclosing at least a portion of the 3-D object is determined. A halftone threshold matrix comprising an array of threshold values is provided. The halftone threshold matrix is converted to provide an M×N×L 3-D array of threshold values. Each material volume coverage vector of the at least a portion is compared with each threshold value at corresponding 3-D locations to select a printable voxel at each 3-D location to convert the at least a portion of the 3-D object into a format suitable for printing.

Claims

1. A method of converting at least a portion of a 3-D object into a format suitable for printing, the method comprising:

(a) determining a material volume coverage vector for each voxel of a 3-D bit map of a 3-D object, each volume coverage vector specifying an amount of each of multiple materials for a corresponding voxel, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location;

(b) determining a rectangular cuboid comprising an M×

N×

L array of voxel locations enclosing at least a portion of the 3-D object;

(c) providing a halftone threshold matrix comprising an array of threshold values;

(d) replicating the halftone threshold matrix to an M×

N×

L 3-D array of threshold values; and

(e) comparing each material volume coverage vector with each threshold value of the replicated 3-D halftone threshold matrix at corresponding 3-D locations to select a printable voxel at each 3-D location to convert the at least a portion of the 3-D object into output data of a format suitable for printing; and

(f) forming the 3-D object using the output data.

2. The method of claim 1, wherein the method further comprises repeating steps (b) to (e) for each portion of the 3-D object.

3. The method of claim 1, wherein comparing each material volume coverage vector comprises

comparing at least a portion of the material volume coverage vectors with the threshold value at their corresponding 3-D locations is performed substantially simultaneously.

4. The method of claim 1, wherein providing a halftone threshold matrix comprises generating a O×

P×

Q 3-D halftone threshold matrix comprising a O×

P×

Q 3-D array of threshold values by converting a predetermined O×

P 2-D halftone threshold matrix into an O×

P×

Q 3-D halftone threshold matrix.

5. The method of claim 4, wherein converting a predetermined O×

P 2-D halftone threshold matrix comprises

determining a third dimension Q of a 3-D halftone threshold matrix based on the percentage area coverage of each 2-D slice of the 3-D object; and

generating 2-D array of threshold values for each level of the determined third dimension.

6. The method of claim 1, wherein replicating the halftone threshold matrix to provide a M×

N×

L 3-D array of threshold values comprises repeating the halftone threshold matrix to fill the M×

N×

L 3-D array.

7. The method of claim 6, wherein replicating the halftone threshold matrix to provide a M×

N×

L 3-D array of threshold values comprises

computing a multiplying factor for each dimension of the halftone threshold matrix to generate the corresponding dimension of the M×

N×

L 3-D array; and

multiplying each dimension of the halftone threshold matrix with the corresponding, computed multiplying factor.

8. The method claim 1, wherein the method further comprises

generating a 3-D bit map of a 3-D object, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location;

and

the step of determining a material volume coverage vector for each voxel of a 3-D bit map comprises determining a material volume coverage vector for each voxel of the generated 3-D bit map.

9. The method of claim 8, wherein the step of generating a 3-D bit map of a 3-D object comprises

determining a vector image in 3-D of a 3-D object;

slicing the 3-D vector image into a plurality of vector slices; and

rasterizing each vector slice;

assembling each rasterized slice to generate a 3-D bit map of the 3-D object,

the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location.

16. The method of claim 1, wherein the material volume coverage vector indicates a likelihood for each of a plurality of different types of material to be deposited in a corresponding voxel.

17. The method of claim 16, wherein the different types of material comprise coalescing agent, coalescence modifier agent and colorant.

18. The method of claim 1, wherein the material volume coverage vector indicates a likelihood that a coalescing agent will and will not be deposited in a corresponding voxel.

10. Apparatus for converting at least a portion of a 3-D object into a format suitable for printing, the apparatus comprising:

a processor to determine a material volume area coverage vector for each voxel of a 3-D bit map of a 3-D object, each volume coverage vector specifying an amount of each of multiple materials for a corresponding voxel, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location; and

to determine a rectangular cuboid comprising an M×

N×

L array of voxel locations enclosing at least a portion of the 3-D object;

a replicator to replicate a provided halftone threshold matrix to an M×

N×

L 3-D array of threshold values; and

a comparator to compare each material volume coverage vector with each threshold value of the replicated 3-D halftone threshold matrix at corresponding 3-D locations to select a printable voxel at each 3-D location to convert the at least a portion of the 3-D object into a format suitable for printing;

wherein the processor is to provide the halftone threshold matrix by generating a O×

P×

Q3-D halftone threshold matrix comprising a O×

P×

Q 3-D array of threshold values by converting a predetermined O×

P 2-D halftone threshold matrix into an O×

P×

Q 3-D halftone threshold matrix,

wherein converting the predetermined O×

P 2-D halftone threshold matrix comprises determining a third dimension Q of a 3-D halftone threshold matrix based on the percentage area coverage of each 2-D slice of the 3-D object, and generating 2-D array of threshold values for each level of the determined third dimension.

11. Apparatus of claim 10, wherein the comparator comprises a plurality of comparator units connected in parallel to compare at least a portion of the material volume coverage vectors with the threshold value at their corresponding 3-D locations substantially simultaneously.

12. Apparatus of claim 10, wherein the apparatus further comprises a preprocessor to generate a 3-D bit map of a 3-D object, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location.

13. Apparatus of claim 10, wherein the replicator, when replicating the halftone threshold matrix, is to provide a M×

N×

L 3-D array of threshold values comprises repeating the halftone threshold matrix to fill the M×

N×

L 3-D array.

15. The computer-readable storage media of claim 13, wherein the media comprises further instructions stored thereon, that when executed, direct a processor to

generate a O×

P×

Q 3-D halftone threshold matrix comprising a O×

P×

Q 3-D array of threshold values by converting a predetermined O×

P 2-D halftone threshold matrix into an O×

P×

Q 3-D halftone threshold matrix.

19. Apparatus of claim 13, wherein replicating the halftone threshold matrix to provide a M×

N×

L 3-D array of threshold values comprises

computing a multiplying factor for each dimension of the halftone threshold matrix to generate the corresponding dimension of the M×

N×

L 3-D array; and

multiplying each dimension of the halftone threshold matrix with the corresponding, computed multiplying factor.

20. The computer-readable storage media of claim 15, the media comprises further instructions stored thereon, that when executed, direct a processor to convert a predetermined O×

P 2-D halftone threshold matrix by;

determining a third dimension Q of a 3-D halftone threshold matrix based on the percentage area coverage of each 2-D slice of the 3-D object; and

generating 2-D array of threshold values for each level of the determined third dimension.

14. A non-transitory computer-readable storage media comprising instructions stored thereon, that when executed;

direct a processor to perform a method comprising;

determining a material volume coverage vector for each voxel of a 3-D bit map of a 3-D object, each volume coverage vector specifying an amount of each of multiple materials for a corresponding voxel, the 3-D bit map comprising a plurality of voxels, each voxel located at a unique 3-D location, the material volume coverage vector indicating a likelihood that a coalescing agent will and will not be deposited in a corresponding voxel;

determining a rectangular cuboid comprising an M×

N×

L array of voxel locations enclosing at least a portion of the 3-D object;

replicating a provided halftone threshold matrix to an M×

N×

L 3-D array of threshold values; and

using the material volume coverage vector and halftone threshold matrix, outputting, to a manufacturing device, a set of output data for manufacturing the 3-D object with the manufacturing device.