Image forming apparatus, method for deriving correction data, and non-transitory computer-readable storage medium

Patent metadata

Field	Value
Publication number	US-11820157-B2
Application number	US-202117354950-A
Country	US
Kind code	B2
Filing date	Jun 22, 2021
Priority date	Jul 15, 2020
Publication date	Nov 21, 2023
Grant date	Nov 21, 2023

Abstract

An image forming apparatus includes an image forming device, a reading device, and circuitry. The image forming device discharges ink droplets through nozzles to form an image on a recording medium conveyed in a first direction. The reading device reads the image formed on the recording medium. The circuitry generates a correction chart that includes patches, located in the first direction and representing different densities from each other, and two marks located at different positions from each other in a second direction perpendicular to the first direction. The circuitry locates opposed end portions of the patches in the second direction outside the two marks in the second direction. The circuitry derives correction data, based on read data of an area of the patches existing inside the two marks in the second direction included in read data provided by the reading device reading the correction chart formed on the recording medium.

First claim

What is claimed is:

1. An image forming apparatus comprising:
an image forming device including a head, the head including a plurality of nozzles and being configured to discharge ink droplets through the plurality of nozzles to form an image on a recording medium conveyed in a first direction;
a reading device configured to read the image formed on the recording medium; and
circuitry configured to generate a correction chart, the correction chart including:
a plurality of patches located in the first direction and representing different densities from each other; and
two marks located at different positions from each other in a second direction perpendicular to the first direction, wherein the two marks are located at positions determined by the circuitry based on a range of flare that affects reading, by the reading device, of the plurality of patches on the recording medium,

the circuitry being configured to locate opposed end portions of the plurality of patches in the second direction outside the two marks in the second direction,
the circuitry being configured to derive correction data, based on read data provided by the reading device reading the correction chart formed on the recording medium, the read data including read data of an area of the plurality of patches existing inside the two marks in the second direction,
the circuitry being configured to derive the correction data, based on the read data of the area of the plurality of patches existing inside the two marks in the second direction.

2. The image forming apparatus according to claim 1 ,
wherein the circuitry is configured to set a length of part or all of the plurality of patches in the first direction to a length including a range of a flare that affects reading, by the reading device, of the plurality of patches in the first direction,
wherein the read data provided by the reading device further includes read data of a rest of the plurality of patches excluding the range in the first direction, and
wherein the circuitry is configured to derive the correction data, based on the read data of the rest of the plurality of patches excluding the range in the first direction.

3. The image forming apparatus according to claim 2 ,
wherein the circuitry is configured to set a length, in the first direction, of one of the plurality of patches representing a highest density to a length including the range.

4. The image forming apparatus according to claim 1 ,
wherein the circuitry is configured, in a case in which the correction chart does not fit in the recording medium, to divide the plurality of patches at a boundary in the first direction into a size according to the recording medium to generate a plurality of correction charts, and
wherein the circuitry is configured to derive the correction data, based on read data provided by the reading device reading the plurality of correction charts.

5. A method for deriving correction data, the method comprising:
generating a correction chart, the correction chart including:
a plurality of patches located in a first direction in which a recording medium is conveyed,
the plurality of patches representing different densities from each other; and
two marks located at different positions from each other in a second direction perpendicular to the first direction, wherein the two marks are located at positions determined based on a range of flare that affects reading of the plurality of patches on the recording medium,

the generating including locating opposed end portions of the plurality of patches in the second direction outside the two marks in the second direction; and
deriving correction data, based on read data provided by a reading device reading the correction chart formed on the recording medium, the read data including read data of an area of the plurality of patches existing inside the two marks in the second direction,
the deriving including deriving the correction data, based on the read data of the area of the plurality of patches existing inside the two marks in the second direction.

6. A non-transitory, computer-readable storage medium storing computer-readable program code that causes a computer to perform a method for deriving correction data, the method comprising:
generating a correction chart, the correction chart including:
a plurality of patches located in a first direction in which a recording medium is conveyed,
the plurality of patches representing different densities from each other; and
two marks located at different positions from each other in a second direction perpendicular to the first direction, wherein the two marks are located at positions determined based on a range of flare that affects reading of the plurality of patches on the recording medium,

the generating including locating opposed end portions of the plurality of patches in the second direction outside the two marks in the second direction; and
deriving correction data, based on read data provided by a reading device reading the correction chart formed on the recording medium, the read data including read data of an area of the plurality of patches existing inside the two marks in the second direction,
the deriving including deriving the correction data, based on the read data of the area of the plurality of patches existing inside the two marks in the second direction.

Assignees

• Sagimori Yuuki
• Ricoh Co Ltd

Inventors

• Sagimori Yuuki

Classifications

• B41J2/362 Primary

  Correcting density variation · CPC title

• B41J2/04508

  aiming at correcting other parameters · CPC title

• B41J2/04541

  Specific driving circuit · CPC title

• B41J2/01 Primary

  Ink jet · CPC title

• H04N1/506 Primary

  Reproducing the colour component signals picture-sequentially, e.g. with reproducing heads spaced apart from one another in the subscanning direction · CPC title