Generating halftone data for a three-dimensional object

• US 10,564,629 B2
• Filed: 10/08/2014
• Issued: 02/18/2020
• Est. Priority Date: 10/08/2014
• Status: Active Grant

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Donovan, David H., Wright, Jacob Tyler
• Primary Examiner(s): Nguyen, Phu K
• Application Number:
  US15/511,906
• Publication Number:
  US 20170246811A1
• Time in Patent Office: 1,959 Days
• Field of Search: 345419
• CPC Class Codes: B29C 64/386 Data acquisition or data processing for additive manufacturing
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes
• 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: H04N 1/405 Halftoning, i.e. converting the picture signal of a continuous-tone original into a corresponding signal showing only two levels

Abstract

A method of forming a three-dimensional object includes non-deterministically generating halftone data for portions of a slice of three-dimensional model data of the three-dimensional object that overlap with a previous slice. The non-deterministically generating halftone data may comprise using randomized initialization for each slice of a three-dimensional object.

Claims

1. A method of forming a three-dimensional object comprising:

non-deterministically generating halftone data for portions of a slice of three-dimensional model data of the three-dimensional object that overlap with a previous slice;

wherein non-deterministically generating halftone data comprises implementing randomized initialization for each slice of a three-dimensional object by shifting a start position of halftone matrix data used to form each slice of the three-dimensional object using a nonintegral multiple of a size of the matrix data.

2. The method of claim 1, in which non-deterministically generating halftone data comprises preloading a number of errors in an error diffusion halftoner.

3. The method of claim 1, in which the halftone data for each successive slice is generated by:

generating error data after generating first halftone data for a first slice of successive slices; and

mathematically associating the error data with continuous tone values when generating second halftone data for a second slice to be placed on the first slice.

4. The method of claim 1, further comprising generating first and second halftone data sets for respective first and second slices of the object based on determined constraints that specify that a first pattern for the first slice be different than a second pattern for the second slice.

5. The method of claim 4, in which, for each slice of the three-dimensional object, a different halftone matrix is selected.

6. An additive manufacturing device, comprising:

a processor; and

a memory communicatively coupled to the processor;

wherein the processor non-deterministically generates halftone data for each of a number of successive slices of three-dimensional model data for a three-dimensional object when at least a portion of each of the successive slices overlap with a previous slice;

wherein non-deterministically generating halftone data comprises implementing randomized initialization for each of the slices of the three-dimensional object by shifting a start position of halftone matrix data used to form each slice of the three-dimensional object using a nonintegral multiple of a size of the matrix data.

7. The additive manufacturing device of claim 6, in which the randomized initialization data is different for adjacent slices throughout the entire three-dimensional object.

8. The additive manufacturing device of claim 6, in which the randomized initialization data comprises data describes a starting position of a matrix halftone at a different location for each slice of the three-dimensional object.

9. The additive manufacturing device of claim 6, in which the halftone data for each successive slice is generated by:

generating error data when generating first halftone data for a first slice; and

mathematically associating the error data with continuous tone values when generating second halftone data for a second slice to be formed on the first slice.

10. The additive manufacturing device of claim 6, in which the halftone data for each successive slice is generated by:

generating an error value at each element location in a contone matrix when generating first halftone data for a first slice; and

passing part of the error value to a corresponding element in a successive slice.

11. A method, comprising:

with a processor of an additive manufacturing device;

determining whether at least a portion of a first slice of three-dimensional object model data overlap at least a portion of a successive slice; and

non-deterministically generating halftone data for a portion of the successive slice of three-dimensional model data defining the three-dimensional object if the first slice overlaps the successive slice;

wherein non-deterministically generating halftone data comprises implementing randomized initialization for each of the successive slices of the three-dimensional object by shifting a start position of halftone matrix data used to form each successive slice of the three-dimensional object using a nonintegral multiple of a size of the matrix data.

12. The method of claim 11, in which in the halftone data for each of the successive slices is generated by:

generating error data when generating first halftone data for the first slice; and

mathematically associating the error data with continuous tone values when generating second halftone data for the successive slice.

13. The method of claim 11, in which non-deterministically generating halftone data comprises preloading a number of errors in an error diffusion halftoner.

14. The method of claim 11, comprising generating first and second halftone data sets for respective first and second slices of the three-dimensional object based on determined constraints that specify that a first pattern for the first slice be different than a second pattern for the second slice.

15. The method of claim 14, in which, for each slice of the three-dimensional object, a different halftone matrix is selected.