System for printing images on a surface and method thereof

Patent metadata

Field	Value
Publication number	US-10308039-B2
Application number	US-201815919215-A
Country	US
Kind code	B2
Filing date	Mar 13, 2018
Priority date	May 29, 2015
Publication date	Jun 4, 2019
Grant date	Jun 4, 2019

Abstract

A system for printing an image includes a robot, a printhead, a laser device, and a reference line sensor. The robot has at least one arm. The printhead is mounted to the arm and is movable by the arm over a surface along a rastering path while printing a new image slice over the surface. The laser device is configured to etch, during printing of the new image slice, a reference line into either the new image slice or into a basecoat at a location adjacent to the new image slice. The reference line sensor is configured to sense the reference line of an existing image slice and transmit a signal to the robot causing the adjustment of the printhead in a manner such that a side edge of the new image slice is aligned with the side edge of the existing image slice.

First claim

What is claimed is:

1. A system for printing an image on a surface, comprising:
a robot having at least one arm;
a printhead mounted to the arm and being movable by the arm over a surface along a rastering path while printing a new image slice over the surface;
a laser device included with the printhead and configured to etch, during printing of the new image slice, a reference line into either the new image slice or into a basecoat at a location adjacent to the new image slice; and
a reference line sensor configured to sense the reference line of an existing image slice and transmit a signal to the robot causing the arm to adjust the printhead in a manner such that a side edge of the new image slice is aligned with the side edge of the existing image slice.

2. The system of claim 1 , wherein:
the robot is configured to adjust a lateral position of the printhead in a manner such that the side edge of the new image slice is maintained in non-gapped and non-overlapping relation with the side edge of the existing image slice.

3. The system of claim 1 , wherein:
the robot is configured to electronically offset nozzles actively ejecting droplets in a manner such that the side edge of the new image slice is maintained in non-gapped and non-overlapping relation with the side edge of the existing image slice.

4. The system of claim 1 , wherein:
the reference line sensor is an optical sensor configured to emit an optical beam and generate a signal representing a lateral location where the optical beam strikes the reference line, and provide real-time alignment feedback to the robot for adjusting the printhead in a manner such that the side edge of the new image slice is maintained in alignment with the side edge of the existing image slice.

5. The system of claim 1 , wherein the reference line sensor is a camera, the system further including:
a light source configured to illuminate the reference line and a surrounding area during printing of the new image slice; and
the camera configured to receive the light emitted by the light source after reflection off of the reference line and the surrounding area, the camera configured to transmit to the robot a signal for determination by the robot of a lateral location of the reference line based on variations in specular reflectivity of the light emitted by the light source for adjustment of the printhead in a manner such that the side edge of the new image slice is maintained in alignment with the side edge of the existing image slice.

6. The system of claim 1 , wherein:
the laser device is configured to etch the reference line as a series of line segments;
the reference line sensor configured to sense the line segments and transmit the signal to the robot; and
the robot configured to determine, based on a rate at which the line segments are sensed as represented by the signal, a printhead velocity during the printing of the new image slice, and adjust the robot such that the printhead is maintained at substantially a same printhead velocity as during the printing of the existing image slice.

7. The system of claim 1 , wherein:
the laser device is configured to etch the reference line as a series of line segments;
the reference line sensor configured to sense the line segments and transmit the signal to the robot; and
the robot configured to operate the printhead in a manner in which an ejection rate of droplets for the new image slice is modulated in correspondence with the line segments of the existing image slice during printing of the new image slice.

8. The system of claim 1 , further including:
at least one high-bandwidth actuator coupling the printhead to an end of the arm; and
the high-bandwidth actuator configured to adjust at least one of an orientation and a position of the printhead relative to the surface during movement of the printhead along the rastering path.

9. The system of claim 1 , further including:
at least one position sensor coupled to the printhead and configured to measure a normal spacing between the printhead and the surface along a direction locally normal to the surface; and
the robot configured to adjust, during printing of the new image slice, a position of the printhead based on the normal spacing measured by the position sensor in such a manner maintaining the normal spacing at a constant value.

10. A system for printing an image on a surface, comprising:
a robot having at least one arm;
a high-bandwidth actuator coupled to an end of the arm;
an inkjet printhead coupled to the high-bandwidth actuator and being movable by the arm over a surface along a rastering path while printing a new image slice over the surface;
a laser device included with the printhead and configured to etch, during printing of the new image slice, a reference line into either the new image slice or into a basecoat at a location adjacent to the new image slice; and
a camera configured to sense the reference line of an existing image slice and transmit a signal to the robot causing the high-bandwidth actuator to adjust the printhead in a manner such that a side edge of the new image slice is maintained in alignment with the side edge of the existing image slice.

11. A method for printing an image on a surface, comprising:
printing, using a printhead mounted to an arm of a robot, a new image slice on the surface while moving the printhead over the surface along a rastering path;
etching, using a laser device, a reference line into either the new image slice or into a basecoat while printing the new image slice;
sensing, using a reference line sensor, the reference line of an existing image slice while printing the new image slice; and
adjusting, using a controller, the printhead based on a sensed position of the reference line in a manner maintaining alignment of a side edge of the new image slice with the side edge of the existing image slice.

12. The method of claim 11 , wherein the step of adjusting the printhead comprises:
adjusting a lateral position of the printhead such that the side edge of the new image slice is maintained in non-gapped and non-overlapping relation with the side edge of the existing image slice.

13. The method of claim 11 , wherein the step of adjusting the printhead comprises:
electronically offsetting groups of nozzles actively ejecting droplets in a manner such that the side edge of the new image slice is maintained in non-gapped and non-overlapping relation with the side edge of the existing image slice.

14. The method of claim 11 , wherein the step of sensing the reference line comprises:
emitting, using an optical sensor, an optical beam toward the reference line;
generating, using the optical sensor, a signal representing a lateral location where the optical beam strikes the reference line; and
transmitting the signal to the robot for adjusting the printhead in a manner maintaining alignment of the side edge of the new image slice with the side edge of the existing image slice.

15. The method of claim 11 , wherein the step of sensing the reference line comprises:
illuminating, using a light source, the reference line and a surrounding area during printing of the new image slice; and
receiving, using a camera, the light emitted by the light source and reflected off the reference line and the surrounding area;
determining, using the camera, a lateral location of the reference line based on variations in specular reflectivity of the light emitted by the light source, and generating a signal representative thereof; and
transmitting the signal to the robot for adjusting the printhead in a manner

Assignees

• Boeing Co

Inventors

• Mathis Dennis R

Classifications

• B41J2/442

  using lasers · CPC title

• B41J3/4073 Primary

  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 title

• B41J2/01

  Ink jet · CPC title

• B41J2/2132

  Print quality control characterised by dot disposition, e.g. for reducing white stripes or banding (methods for local corrections by dot omission, image edge enhancement, or multi-pass mask selection G06K15/102; colour conversion H04N1/40) · CPC title