System and method for adjusting printhead operations in a direct-to-object printer having a fixed printhead array

• US 9,975,327 B1
• Filed: 05/18/2017
• Issued: 05/22/2018
• Est. Priority Date: 05/18/2017
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Yang, Xin, McConville, Paul J., Steurrys, Christine A., Stookey, David R., Frachioni, Martin L., Breed, Dale R.
• Primary Examiner(s): Vo, Anh T. N.
• Application Number:
  US15/598,807
• Time in Patent Office: 369 Days
• CPC Class Codes: B41J 11/00214 using UV radiation
• CPC Class Codes: B41J 2/21 for multi-colour printing
• CPC Class Codes: B41J 2/2132 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 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: B41J 3/40731 Holders for objects, e. g. holders specially adapted to the shape of the object to be printed or adapted to hold several objects
• CPC Class Codes: B41J 3/4078 Printing on textile
• CPC Class Codes: B41J 3/50 Mechanisms producing characters by printing and also producing a record by other means , e.g. printer combined with RFID writer
• CPC Class Codes: B41J 3/543 with multiple inkjet print heads B41J2/17503, B41J2/2103 take precedence

Abstract

A direct-to-object printer includes a plurality of imaging devices that generates image data of an object secured in a holder before the holder and the object pass a plurality of printheads for printing an ink image on the object. A controller receives the image data and converts it to an object profile. The controller operates ejectors in the printheads with reference to the object profile to attenuate inconsistent ink image density and ink image distortion.

Claims

1. A printing system comprising:

a plurality of printheads, each printhead in the plurality of printheads being configured to eject marking material;

a member having a first end and a second end, the plurality of printheads being positioned opposite the member and between the first end and the second end of the member;

a holder configured to hold an object and to move along the member between the first end and the second end of the member;

an actuator operatively connected to the holder to enable the actuator to move the holder along the member to enable the object to move past the printheads to receive marking material from the printheads in the plurality of printheads;

a plurality of imaging device, the plurality of imaging devices being positioned between the first end of the member and the plurality of printheads, each imaging device in the plurality of imaging devices being configured to generate image data of a portion of the object opposite the imaging device as the object passes the plurality of imaging devices; and

a controller operatively connected to the plurality of printheads, the actuator, and the plurality of imaging devices, the controller being configured to operate the actuator to move the holder and the object along the member, to operate the imaging devices to generate image data of the object in response to the object being opposite the plurality of imaging devices, to generate an object profile with reference to the generated image data received from the imaging devices, and to operate ejectors within the printheads of the plurality of printheads with reference to the generated object profile.

2. The printing system of claim 1 wherein the plurality of imaging devices is a plurality of cameras operatively connected to the controller for delivery of the image data generated by each camera in the plurality of cameras to the controller.

3. The printing system of claim 2 wherein the printheads in the plurality of printheads are fixed printheads.

4. The printing system of claim 3, the controller being further configured to operate ejectors that are further from the object than ejectors closer to the object at a first frequency and to operate the ejectors closer to the object at a second frequency, the first frequency being greater than the second frequency.

5. The printing system of claim 4, the controller being further configured to operate ejectors that are further from the object than ejectors closer to the object before operating the ejectors closer to the object to enable drops of marking material from the ejectors further from the object to arrive at the object simultaneously with drops ejected from the ejectors closer to the object.

6. The printing system of claim 3, the controller being further configured to operate ejectors that are further from the object than ejectors closer to the object before operating the ejectors closer to the object to enable drops of marking material from the ejectors further from the object to arrive at the object simultaneously with drops ejected from the ejectors closer to the object.

7. The printing system of claim 6, the controller being further configured to operate ejectors that are further from the object than ejectors closer to the object at a first frequency and to operate the ejectors closer to the object at a second frequency, the first frequency being greater than the second frequency.

8. The printing system of claim 3 further comprising:

an ultraviolet (UV) lamp configured to emit light in an UV range to cure UV curable marking material ejected from the plurality of printheads.

9. The printing system of claim 3 wherein the plurality of cameras are arranged in semi-circular pattern opposite the member.

10. The printing system of claim 3, the controller being further configured to operate the actuator to maintain the holder and the object opposite the plurality of cameras for a predetermined period of time.

11. The printing system of claim 3, the controller being further configured to identify an object surface area ratio with reference to the object profile.

12. The printing system of claim 3, the controller being further configured to identify a printhead-to-object distance with reference to the object profile.

13. A method for operating a printer comprising:

operating with a controller an actuator operatively connected to a holder to move the holder and an object secured in the holder along a member to which the holder is mounted;

operating with the controller a plurality of imaging devices to generate image data of the object in response to the object being opposite the plurality of imaging devices;

generating with the controller an object profile with reference to the generated image data received from the plurality of imaging devices; and

operating with the controller ejectors within a plurality of printheads with reference to the generated object profile, the printheads in the plurality of printheads being fixed printheads.

14. The method of claim 13, the operation of the plurality of imaging devices further comprising:

operating a plurality of cameras with the controller to generate the image data.

15. The method of claim 13 further comprising:

operating with the controller ejectors that are further from the object than ejectors closer to the object at a first frequency; and

operating the ejectors closer to the object at a second frequency, the first frequency being greater than the second frequency.

16. The method of claim 15 further comprising:

operating with the controller ejectors that are further from the object than ejectors closer to the object before operating the ejectors closer to the object to enable drops of marking material from the ejectors further from the object to arrive at the object simultaneously with drops ejected from the ejectors closer to the object.

17. The method of claim 14 further comprising:

operating with the controller ejectors that are further from the object than ejectors closer to the object before operating the ejectors closer to the object to enable drops of marking material from the ejectors further from the object to arrive at the object simultaneously with drops ejected from the ejectors closer to the object.

18. The method of claim 17 further comprising:

operating with the controller ejectors that are further from the object than ejectors closer to the object at a first frequency and to operate the ejectors closer to the object at a second frequency, the first frequency being greater than the second frequency.

19. The method of claim 14 further comprising:

operating with the controller an ultraviolet (UV) lamp to emit light in an UV range to cure UV curable marking material ejected from the plurality of printheads.

20. The method of claim 14 further comprising:

operating with the controller the actuator to maintain the holder and the object opposite the plurality of cameras for a predetermined period of time.

21. The method of claim 14 further comprising:

identifying with the controller an object surface area ratio with reference to the object profile.

22. The method of claim 14 further comprising:

identifying with the controller a printhead-to-object distance with reference to the object profile.