Imaging apparatus and method for reducing banding

Patent metadata

Field	Value
Publication number	US-10315434-B2
Application number	US-201715397090-A
Country	US
Kind code	B2
Filing date	Jan 3, 2017
Priority date	Oct 14, 2015
Publication date	Jun 11, 2019
Grant date	Jun 11, 2019

Abstract

An imaging apparatus includes a print engine having a printhead that generates ink drops, and a printhead carrier that carries the printhead in a first direction and in a second direction. A controller determines an initial print direction based on ink drop information obtained by printing patches in the first direction and in the second direction. The controller is operatively coupled to the print engine to print an image based on the initial print direction.

First claim

What is claimed is:

1. An imaging apparatus, comprising:
a print engine having a printhead that generates ink drops, and having a printhead carrier that carries the printhead in a first direction and in a second direction;
a sensor; and
a controller operatively coupled to the print engine and to the sensor, the controller executing program instructions to:
operate the print engine to print a first patch on a print media sheet with the printhead being moved by the printhead carrier in the first direction;
operate the print engine to print a second patch on the print media sheet with the printhead being moved by the printhead carrier in the second direction, the second direction being opposite to the first direction;
operate the sensor to determine a first characteristic of the first patch;
operate the sensor to determine a second characteristic of the second patch;
compare the first characteristic of the first patch with the second characteristic of the second patch to determine an initial print direction of the printhead that reduces horizontal banding in forming a printed image; and
operate the print engine to print the image based on the initial print direction, wherein:
the first characteristic is a first luminance L* value and the second characteristic is a second luminance L* value; and
the controller selects as the initial print direction the first direction if the first luminance L* value is less than the second luminance L* value, and selects as the initial print direction the second direction if the second luminance L* value is less than the first luminance L* value.

2. The imaging apparatus of claim 1 , wherein the printhead is a monochrome printhead.

3. The imaging apparatus of claim 1 , wherein the printhead is a monochrome printhead, and further including a color printhead, wherein the printhead carrier carries both the monochrome printhead and the color printhead in the first direction and in the second direction.

4. The imaging apparatus of claim 1 , wherein the sensor is a scanner.

5. The imaging apparatus of claim 1 , wherein the sensor is mounted to the printhead carrier.

6. The imaging apparatus of claim 1 , wherein the sensor is an optical sensor.

Assignees

• Funai Electric Co

Inventors

• Barkley Lucas D
• Olson Stephen T

Classifications

• B41J2/21

  for multi-colour printing · CPC title

• B41J2/2132 Primary

  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

• B41J19/142

  with a reciprocating print head printing in both directions across the paper width · CPC title

• B41J19/145

  Dot misalignment correction · CPC title

• B41J2/2135

  Alignment of dots · CPC title