System For Controlling Operation Of A Printer During Three-Dimensional Object Printing With Reference To A Distance From The Surface Of Object

• US 20150352839A1
• Filed: 06/06/2014
• Published: 12/10/2015
• Est. Priority Date: 06/06/2014
• Status: Active Grant

• Current Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Original Assignee: Xerox Corporation (Xerox Holdings Corp.)
• Inventors: Folkins, Jeffrey J., Donaldson, Patricia J.
• Granted Patent: US 9,738,032 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: B29C 64/112 using individual droplets, e.g. from jetting heads
• CPC Class Codes: B29C 64/393 for controlling or regulating additive manufacturing processes
• CPC Class Codes: B33Y 50/02 for controlling or regulating additive manufacturing processes

Abstract

A controller in a printer operates one or more printheads in the printer with reference to a predetermined height of material above a surface of a member and a height of a top layer of material above the surface of the member. The height of the top layer is identified with reference to a first sensor that generates data corresponding to a height of a face of one of the printheads above the surface of the member and a second sensor that generates data corresponding to a distance between the face of one of the printheads and the top layer of material.

Claims

1. A printer comprising:

a member having a surface configured to support formation of an object on the member;

one or more printheads, each printhead being configured with ejectors to eject one or more materials; and

a controller operatively connected to the printhead, the controller being configured to operate the one or more printheads to eject material onto the surface of the member or onto material previously ejected by the one or more printheads with reference to a predetermined height for each material above the surface of the member at a plurality of positions in a plane parallel to a portion of the surface of the member and the one or more printheads.

2. The printer of claim 1 further comprising:

a sensor configured to generate a first measurement corresponding to a distance between a face of a printhead in the one or more printheads and a top layer of previously ejected material, and to generate a second measurement corresponding to a distance between the face of the printhead in the one or more printheads and the surface of the member; and

the controller being operatively connected to the sensor and the controller being further configured to identify the distance between the surface of the member and the top layer of the previously ejected material at each position in the plurality of positions with reference to the first measurement and the second measurement.

3. The printer of claim 2, the sensor further comprising:

a first sensor configured to generate the first measurement;

a second sensor configured to generate the second measurement; and

the controller is operatively connected to the first sensor and the second sensor to receive the first measurement from the first sensor and to receive the second measurement from the second sensor.

4. The printer of claim 2, the controller being further configured to identify the distance between the surface of the member and the top layer of the previously ejected material at each position in the plurality of positions as a difference between the first measurement and the second measurement.

5. The printer of claim 3 wherein the first sensor is an optical sensor.

6. The printer of claim 5 wherein the optical sensor is a profilometer.

7. The printer of claim 3 wherein the second sensor is an encoder.

8. The printer of claim 1 wherein the member is a platen with a planar surface.

9. The printer of claim 1 wherein the member is circular and is configured to rotate in a plane parallel to the face of the printhead.

10. The printer of claim 1, the controller being configured to operate the one or more printheads to eject drops of material having a volume that is less than previously ejected drops of the material at one position in the plurality of positions in response to a difference between the top layer of the material and the predetermined height for the material above the surface of the member at the one position in the plurality of positions being less than a predetermined threshold.

11. The printer of claim 1, the controller being configured to operate the one or more printheads to eject drops of a first material onto previously ejected drops of a second material at one position in the plurality of positions, the first material having different properties than the second material.

12. The printer of claim 11, the controller being configured to operate the one or more printheads to eject the drops of the first material with a first volume and to eject the drops of the second material with a second volume, the first volume being different than the second volume.

13. The printer of claim 2, the controller being configured to operate the one or more printheads at a first ejection frequency and to operate the one or more printheads at a second ejection frequency, which is different than the first ejection frequency, in response to a difference between the distance between the surface of the member and the top layer of the previously ejected material and the predetermined height of the material being less than a predetermined threshold.

14. The printer of claim 2 further comprising:

one or more actuators operatively coupled to one or more printheads or the member; and

the controller being operatively connected to the one or more actuators, the controller being configured to operate the one or more actuators to move the one or more printheads or the member at a first speed while the printhead is being operated to eject drops of material and to operate the one or more actuators to move the one or more printheads or the member at a second speed, which is different than the first speed, while the printhead is being operated to eject drops of material in response to a difference between the distance between the surface of the member and the top layer of the previously ejected material and the predetermined height of the material being less than a predetermined threshold.

15. The printer of claim 2 further comprising:

one or more actuators operatively coupled to one or more printheads or the member; and

the controller being operatively connected to the one or more actuators, the controller being configured to operate the one or more actuators to move the sensor at a first speed over the member to generate a plurality of first measurements and a plurality of second measurements and to operate the one or more actuators to move the sensor at a second speed, which is different than the first speed, over the member to generate another plurality of first measurements and another plurality of second measurements in response to a difference between the distance between the surface of the member and the top layer of the previously ejected material and the predetermined height of the material being less than a predetermined threshold.

16. The printer of claim 2 further comprising:

one or more actuators operatively coupled to the member;

a curing station; and

the controller being operatively connected to the curing station and the one or more actuators, the controller being configured to operate the one or more actuators to move the member to a position opposite the curing station, to operate the curing station at a first intensity and to operate the curing station at a second intensity, which is different than the first intensity, in response to a difference between the distance between the surface of the member and the top layer of the previously ejected material and the predetermined height of the material being less than a predetermined threshold.

17. The printer of claim 2 further comprising:

one or more actuators operatively coupled to the member;

a curing station;

the sensor being further configured to detect a color of a previously eject material; and

the controller being operatively connected to the curing station and the one or more actuators, the controller being configured to operate the one or more actuators to move the member to a position opposite the curing station, to operate the curing station at a first curing intensity and to operate the curing station at a second intensity, which is different than the first intensity, in response to a top layer of previously ejected material being detected as being a predetermined color.