Apparatus and method for printing on articles having a non-planar surface

• US 8,459,760 B2
• Filed: 06/24/2009
• Issued: 06/11/2013
• Est. Priority Date: 06/24/2008
• Status: Active Grant

• Current Assignee: Plastipak Packaging Incorporated (Plastipak Holdings Incorporated)
• Original Assignee: Plastipak Packaging Incorporated (Plastipak Holdings Incorporated)
• Inventors: Uptergrove, Ronald L., Senta, Manish K.
• Primary Examiner(s): Luu, Matthew
• Assistant Examiner(s): Seo, Justin
• Application Number:
  US12/490,564
• Publication Number:
  US 20090314170A1
• Time in Patent Office: 1,448 Days
• Field of Search: None
• US Class Current: 347/2
• CPC Class Codes: B41F 17/00 Printing apparatus or machines of special types or for particular purposes, not otherwise provided for
• CPC Class Codes: B41J 11/00 Devices or arrangements of selective printing mechanisms, e.g. ink-jet printers or thermal printers, for supporting or handling copy material in sheet or web form script supports connected to the typewriter or printer B41J29/15
• CPC Class Codes: B41J 11/008 Controlling printhead for accurately positioning print image on printing material, e.g. with the intention to control the width of margins
• CPC Class Codes: B41J 3/00 Typewriters or selective printing or marking mechanisms characterised by the purpose for which they are constructed
• 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: B41M 5/0082 Digital printing on bodies of particular shapes sublimation or volatilisation of pre-printed design B41M5/035
• CPC Class Codes: B41M 5/0088 by ink-jet printing

Abstract

A method for printing on an article having a non-planar surface in an embodiment includes obtaining coordinates or a geometry for a non-planar surface of an article; determining a tangent orientation for a print head in three dimensions; and using the tangent orientation and positioning the print head relative to the non-planar surface of the article. Embodiments of apparatus for printing on articles having non-planar surfaces are also disclosed.

Claims

1. A method for printing on an article having a non-planar surface, the method comprising:

obtaining coordinates or a geometry for a non-planar surface of an article;

determining a tangent orientation for a print head in three dimensions; and

using the tangent orientation and positioning the print head relative to the non-planar surface of the article,

wherein the positioning of the print head involves a sabre angle, a cross process angle, and a process angle; and

the sabre angle is used to calculate the cross process angle and the process angle; and

based on the desired print resolution, sabre angle, and print dimensions, points are selected along or about a sabre line; and

a minimum or specified number of points are used to refine tangents at one or more points on the non-planar surface.

2. The method of claim 1, including selecting a range of points based on specified or determined print width associated with a printing surface or substrate.

3. The method of claim 1, wherein the geometry of the non-planar surface is identified from or provided by a common reference entity.

4. The method of claim 3, wherein the common reference entity is provided by three-dimensional drafting or modeling software.

7. The method of claim 1, wherein the coordinates or geometry for the non-planar surface are determined prior to calculating one or more angles associated with the positioning of the print head.

8. The method of claim 1, including:

providing an article with a non-planar surface having a print area or print region;

providing or obtaining a desired print resolution and an associated sabre line;

selecting or identifying a number of points near the sabre line that are on or within the print area or print region;

determining a tangent for the non-planar surface; and

positioning a print head relative to said article using information associated with the tangent.

9. The method of claim 1, including:

providing a plurality of points in two dimensions, the plurality of points representing points selected or identified in connection with a print surface/substrate;

providing a sabre line with a sabre angle;

selecting a plurality of points on the print surface and identifying three-dimensional coordinates at the print surface for the plurality of points;

providing a minimum number of points along or about the sabre line;

measuring the offset distances between successive points;

assessing a line placement on the surface with respect to the sabre line;

calculating the distance between coordinates; and

applying trigonometric functions between distances calculated between coordinates and the offset distances between each coordinate point to provide a print angle for that point.

10. The method of claim 9, including providing print angles for a plurality of points.

5. A method for priming on an article having a non-planar surface, the method comprising:

obtaining coordinates or a geometry for a non-planar surface of an article;

determining a tangent orientation for a print head in three dimensions; and

using the tangent orientation and positioning the print head relative to the non-planar surface of the article,

wherein the positioning of the print head involves a sabre angle, a cross process angle, and a process angle; and

the sabre angle is used to calculate the cross process angle and the process angle; and

based on the desired print resolution, sabre angle, and print dimensions, points are selected along or about a sabre line; and

offset distances between successive points are determined.

6. The method of claim 5, wherein the determination of offset distances involves using a least-squares analysis or a line-fitting calculation.

11. A method for printing on an article having a non-planar surface, the method comprising:

(a) selecting a plurality of points based on a print width on an identified printing surface;

(b) identifying coordinates with respect to a common reference point;

(c) selecting a plurality of points along a sabre line, the sabre line having a sabre angle;

(d) obtaining an offset distance between successive points along the sabre line;

(e) selecting a coordinate that describes the curvature of the printing surface;

(f) determining a print angle based on the selected coordinate;

(g) using a distance equation to determine the distances between identified coordinates; and

(h) using trigonometric functions between the determined distance between identified coordinates and the offset distance to provide a print angle for a specific point.

12. The method of claim 11, including repeating one or more steps (d) through (h) for a plurality of the points selected in step (a).

13. The method of claim 11, including plotting a plurality of points describing the nature of point deviation or the tangent/slope at points at the reference sabre angle.

14. The method of claim 13, including using line fitting techniques to find an average angle for the slope associated with the plotted points.

15. The method of claim 11, wherein one or more steps of the method are repeated for a non-sabre angle.

16. An apparatus for printing on an article having a non-planar surface, the apparatus comprising:

a print head including a plurality of nozzles;

a means for determining a tangent for a print surface or print substrate on a non-planar print surface of said article; and

a means for positioning the print head relative to the non-planar surface based on the determined tangent using a sabre angle, a cross process angle, and a process angle;

wherein the apparatus is configured to use the sabre angle to calculate the cross process angle and the process angle;

the apparatus is configured to select points along or about a sabre line based on the desired print resolution, sabre angle, and print dimensions; and

the apparatus is configured to use a minimum or specified number of points to refine tangents at one or more points on the non-planar surface.

17. The apparatus of claim 16, wherein the means for positioning the print head comprises a mechanical arm providing at least two degrees of rotational freedom.