Apparatus and methods for servicing 3D printers

• US 7,824,001 B2
• Filed: 11/30/2004
• Issued: 11/02/2010
• Est. Priority Date: 09/21/2004
• Status: Active Grant

• Current Assignee: 3D Systems, Inc. (3D Systems Corporation)
• Original Assignee: Z CORPORATION (A Holdings Corp.)
• Inventors: Hernandez, Andres Tomas, Kinsley, Joshua P., Fienup, William James, Zengerle, Walter H. III, Berlin, Andrew A.
• Primary Examiner(s): Nguyen; Lam S
• Application Number:
  US11/000,100
• Publication Number:
  US 20060061613A1
• Time in Patent Office: 2,163 Days
• Field of Search: 347/5, 347/9, 347 14- 15, 347/19, 347/42, 347/12, 347/13
• US Class Current: 347/19
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B33Y 40/00 Auxiliary operations or equipment, e.g. for material handling
• CPC Class Codes: B41J 2/16532 by applying vacuum only
• CPC Class Codes: B41J 2/16538 with brushes or wiper blades perpendicular to the nozzle plate
• CPC Class Codes: B41J 2/16552 using cleaning fluids
• CPC Class Codes: B41J 2/16585 for paper-width or non-reciprocating print heads
• CPC Class Codes: B41J 2/1752 Mounting within the printer
• CPC Class Codes: B41J 29/393 Devices for controlling or analysing the entire machine ; Controlling or analysing mechanical parameters involving printing of test patterns
• CPC Class Codes: B41J 3/4073 Printing on three-dimensional objects not being in sheet or web form, e.g. spherical or cubic objects B41J3/283, B41J3/286 take precedence; building up a 3D object using individual droplets from jetting heads B29C64/112
• CPC Class Codes: H04N 1/6033 using test pattern analysis H04N1/6055 takes precedence

Abstract

The invention relates to apparatus and methods for producing three-dimensional objects and auxiliary systems used in conjunction with the aforementioned apparatus and methods. The apparatus and methods involve 3D printing and servicing of the equipment used in the associated 3D printer.

Claims

1. A method of determining and applying correction factors for aligning a plurality of printheads, the method comprising:

printing a test pattern on a build surface;

analyzing the test pattern to determine a harmonic content thereof at at least one frequency; and

determining correction factors based on the harmonic content of the test pattern, herein a correction factor is determined by locating a minimum value of an analytical curve that has been fitted to a representative set of harmonic content values determined for a range of nominal test bar displacements; and

adjusting timing of a firing signal to at least one of the plurality of pintheads based on at least one correction factor,

wherein the correction factors are determined from a set of third harmonic content values.

2. The method of claim 1, further comprising the step of generating a set of electrical signals representative of the test pattern, wherein the correction factors are based on the harmonic content of the electrical signals, the step of generating electrical signals comprising:

illuminating the test pattern; and

measuring reflectance of the test pattern at predetermined locations.

3. The method of claim 2, wherein the step of analyzing the test pattern comprises analyzing the electrical signals and determining the harmonic content of the signals at a predetermined frequency by application of at least one of an analog filter and a digital filter.

4. The method of claim 1, wherein the test pattern comprises:

a plurality of substantially evenly spaced solid reference lines; and

a plurality of test lines disposed in an alternating pattern with the plurality of reference lines, wherein each of the test lines comprises at least one bar of a non-reference color.

5. The method of claim 4, wherein the plurality of lines is oriented substantially parallel to a fast-axis printhead travel and a second plurality of lines is oriented substantially perpendicular to the fast-axis printhead travel.

6. A method of determining and applying correction factors for aligning a plurality of printheads, the method comprising:

printing a test pattern on a build surface;

analyzing the test pattern to determine a harmonic content thereof at at least one frequency; and

determining correction factors based on the harmonic content of the test pattern, herein a correction factor is determined by locating a minimum value of an analytical curve that has been fitted to a representative set of harmonic content values determined for a range of nominal test bar displacements; and

adjusting timing of a firing signal to at least one of the plurality of pintheads based on at least one correction factor,

wherein the correction factors are determined from a set of first harmonic content values.