Dual pass uniformity printing compensation mechanism

Patent metadata

Field	Value
Publication number	US-11077674-B2
Application number	US-201916557397-A
Country	US
Kind code	B2
Filing date	Aug 30, 2019
Priority date	Feb 21, 2017
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A printing system is disclosed. The printing system includes a printer to print image data to a medium. The printer includes a first pass channel including a first set of pel forming elements to print a first component of the image data and a second pass channel including a second set of pel forming elements to print a second component of the image data, wherein the first component of the image data and the second component of the image data occupy a same region on the print medium. The printing system also includes a print controller to perform uniformity compensation based on a combined compensation of the first pass channel and the second pass channel.

First claim

What is claimed is:

1. A printing system comprising:
a print controller to perform a calibration of a first pass channel and a second pass channel based on a combined compensation of a first component of an image data to print at a first set of pixel (pel) forming elements of the first pass channel and a second component of the image data to print at a second set of pel forming elements of the second pass channel, wherein the combined compensation is based on measurement data corresponding to a first of a plurality of regions printed on a print medium by the first pass channel and the second pass channel, the first set of pel forming elements are separate from the second set of pel forming elements, and wherein the first component of the image data and the second component of the image data occupy the first of the plurality of regions on the print medium, and each of the plurality of regions forms a column on the print medium.

2. The printing system of claim 1 , further comprising a measurement module to obtain the measurement data for each pel forming element in the first and second set of pel forming elements.

3. The printing system of claim 1 , wherein the print controller comprises a halftone calibration module to generate a first calibrated halftone for the first pass channel and a second calibrated halftone for the second pass channel based on the measurement data.

4. The printing system of claim 3 , wherein generating the first and second calibrated halftones comprises receiving first and second un-calibrated halftones, transforming threshold values in the first and second un-calibrated halftones via an inverse transfer function to generate first and second calibrated halftone threshold values; and generating the first and second calibrated halftones based on the calibrated halftone threshold values.

5. The printing system of claim 4 , wherein the halftone calibration module computes the inverse transfer function to achieve a target response based on the measurement data.

6. The printing system of claim 5 , wherein the print controller further comprises a halftoning module to perform halftoning on the image data at the first pass channel using the first calibrated halftone and at the second pass channel using the second calibrated halftone.

7. The printing system of claim 6 , wherein the first pass channel prints the first component of the image data using the first calibrated halftone and the second pass channel prints the second component of the image data using the second calibrated halftone.

8. The printing system of claim 1 , wherein the image data is replicated for the first pass channel and the second pass channel.

9. The printing system of claim 6 , wherein obtaining the measurement data comprises receiving test input image data, perform halftoning on the test input image data at the first pass channel using the first un-calibrated halftone and at the second pass channel using the second un-calibrated halftone and printing the test input image data at the first pass channel and the second pass channel.

10. The printing system of claim 1 , wherein the print controller further performs color compensation by combining two or more colors.

11. The printing system of claim 1 further comprising:
a printer to print the image data to the print medium; including:
the first pass channel to print the first component of the image data; and
the second pass channel to print the second component of the image data.

12. The printing system of claim 1 , wherein the first of the plurality of regions is a single pel width.

13. A method comprising:
performing a calibration of a first pass channel and the second pass channel based on a combined compensation of a first component of the image data to print at a first pass channel including a first set of one or more pixel (pel) forming elements and a second component of the image data to print at a second pass channel including a second set of one or more pel forming elements, wherein the first component of the image data and the second component of the image data occupy a first of a plurality of regions on the print medium, and each of the plurality of regions forms a column on a print medium, the first set of pel forming elements are separate from the second set of pel forming elements, and wherein the combined compensation is based on measurement data corresponding to a the first of the plurality of regions printed by the first pass channel and the second pass channel.

14. The method of claim 13 , further comprising obtaining the measurement data for each pel forming element in the first and second set of pel forming elements.

15. The method of claim 13 , further comprising:
generating a first calibrated halftone for the first pass channel; and
generating a second calibrated halftone for the second pass channel based on the measurement data.

16. The method of claim 15 , wherein generating the first and second calibrated halftones comprises:
receiving first and second un-calibrated halftones;
transforming threshold values in the first and second un-calibrated halftones via an inverse transfer function to generate first and second calibrated halftone threshold values; and
generating the first and second calibrated halftones based on the calibrated halftone threshold values.

17. The method of claim 16 , further comprising computing the inverse transfer function to achieve a target response based on the measurement data.

18. The method of claim 17 , further comprising:
performing halftoning on the image data at the first pass channel using the first calibrated halftone; and
performing halftoning at the second pass channel using the second calibrated halftone.

19. The method of claim 15 , wherein the first pass channel prints the first component of the image data using the first calibrated halftone and the second pass channel prints the second component of the image data using the second calibrated halftone.

20. The method of claim 13 , wherein the image data is replicated for the first pass channel and the second pass channel.

21. The method of claim 18 , wherein obtaining the measurement data comprises receiving test input image data, perform halftoning on the test input image data at the first pass channel using the first un-calibrated halftone and at the second pass channel using the second un-calibrated halftone and printing the test input image data at the first pass channel and the second pass channel.

22. The method of claim 13 , further comprising performing color compensation by combining two or more colors.

23. The method of claim 13 , wherein the first of the plurality of regions is a single pel width.

Assignees

• Stanich Mikel F
• Gurudath Nikita
• Ernst Larry
• Manchester William E
• Ricoh Co Ltd

Inventors

• Stanich Mikel F
• Gurudath Nikita
• Ernst Larry
• Manchester William E

Classifications

• H04N1/603

  controlled by characteristics of the picture signal generator or the picture reproducer · CPC title

• G06K15/027

  Test patterns and calibration (arrangements for controlling or analysing printing mechanisms of typewriters or selective printing units B41J29/393 takes precedence; colour correction using test pattern analysis in general H04N1/6033) · CPC title

• B41J2/52 Primary

  Arrangement for printing a discrete number of tones, not covered by group B41J2/205, e.g. applicable to two or more kinds of printing or marking process (B41J2/525 takes precedence) · CPC title

• G06K15/18

  Conditioning data for presenting it to the physical printing elements (for data conditioning specific to a type of printer see subgroups G06K15/028 - G06K15/14; print job translation or parsing G06F3/1244) · CPC title

• G06K15/105

  Multipass or interlaced printing · CPC title