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Compensation method for overlapping print heads of an ink jet printer

Imported: 24 Feb '17 | Published: 06 Jan '04

James J. Haflinger

USPTO - Utility Patents

Abstract

A system and method of ink jet printing in a printer having more than one print head is disclosed. The printing results in improved image quality by dithering the transition from one print head to the next and by individually adjusting the timing of the firing of each of the print heads. This allows the printer to create a better quality image in instances of horizontal or vertical misalignment of the print heads, without the need for costly and problematic mechanical systems.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of one type of an ink jet printer system.

FIG. 2 is a schematic representation of the placement of two print heads with respect to one another.

FIG. 3 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of a printer having two correctly aligned print heads that has printed several columns along the swath direction.

FIG. 4 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer having two print heads that are horizontally misaligned.

FIG. 5 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer having two print heads that are vertically misaligned.

FIG. 6 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer having two print heads that are horizontally and vertically misaligned.

FIG. 7 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer having two correctly aligned print heads that uses dithering to improve the print quality.

FIG. 8 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer having two print heads that are vertically misaligned utilizing dithering to improve the image quality.

FIG. 9 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer having two print heads that are horizontally and vertically misaligned, and where dithering is used to improve the image quality.

FIG. 10 is an illustration of the ink droplets deposited in a single-pass full color fill by the overlapping region of an ink jet printer employing an example of dithering and timing offset to correct horizontal and vertical misalignment.

Claims

1. A method of by a printer having at least first and second print heads of the same color, the method comprising the steps of:

2. A method of depositing an image onto a print medium by a printer having at least a first print head and a second print head containing the same color, said method comprising:

3. In an ink jet printer having at least two common color print heads with overlapping segments, a method of improving print quality, the method comprising dithering between nozzles in the overlapping segments such that at least one raster line has some ink droplets deposited by a first one of said at least two print heads and some ink droplets deposited by a second one of said at least two print heads.

4. A method of improving print quality in an ink jet printer having at least first and second common color print heads positioned so as to define a first region of nozzles on each print head that does not overlap with the other print head and a second region of nozzles on each print head that overlaps with a region of nozzles of the other print head, said method comprising allocating ink deposition between the second region of nozzles on said first and second print heads so as to form a smooth transition between depositing all ink with said first print head and depositing all ink with said second print head.

5. An inkjet printer comprising:

6. An inkjet printer comprising:

7. An inkjet printer having at least first and second common color print heads with corresponding first and second overlapping segments, comprising:

8. The inkjet printer of claim 7, wherein the means for automatically adjusting the timing of the deposition of the discrete ink droplets includes a CCD array and a timing control circuit.