# US 11,298,955 B2 · Liquid discharge apparatus, control method, and recording medium

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- Number: US 11,298,955 B2
- Document ID: US11298955B2
- Status: Granted
- Kind: B2
- Application number: 16/815,184
- Filed: 2020-03-11
- Published: 2020-09-24
- Granted: 2022-04-12
- Earliest claimed: 2019-03-19
- Assignees: Ricoh Company, Ltd.
- Applicants: Yuri Suetsugu
- Inventors: Yuri Suetsugu
- Web page: https://patentgrep.com/patent/US11298955B2

## CPC

- B41J 2/2132: {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)}
- B41J 2/04501: {Control methods or devices therefor, e.g. driver circuits, control circuits}
- B41J 2/2135: {Alignment of dots}
- B41J 25/308: with print gap adjustment mechanisms
- G06K 15/105: {Multipass or interlaced printing}
- B41J: TYPEWRITERS; SELECTIVE PRINTING MECHANISMS, i.e. MECHANISMS PRINTING OTHERWISE THAN FROM A FORME; CORRECTION OF TYPOGRAPHICAL ERRORS
- G06K: GRAPHICAL DATA READING (image or video recognition or understanding G06V); PRESENTATION OF DATA; RECORD CARRIERS; HANDLING RECORD CARRIERS

## Abstract

A liquid discharge apparatus according to an embodiment of the present disclosure includes: a memory; a hardware processor coupled to the memory and configured to scan a carriage having a liquid discharge head in a main-scanning direction and control discharge of liquid from the liquid discharge head; a roller rotated by a motor to convey a medium in a sub-scanning direction; and an image sensor configured to image a liquid discharged portion on the medium. The hardware processor shifts channels of the liquid discharge head on which discharge of liquid is valid, depending on thickness of stripe-like density unevenness detected by the image sensor.

## Claims

### Claim 1

A liquid discharge apparatus comprising:
a memory;
a hardware processor coupled to the memory and configured to scan a carriage having a liquid discharge head in a main-scanning direction and control discharge of liquid from the liquid discharge head;
a roller rotated by a motor to convey a medium in a sub-scanning direction; and
an image sensor configured to image a liquid discharged portion on the medium,
wherein the hardware processor shifts channels of the liquid discharge head on which discharge of liquid is valid, depending on a thickness of a stripe-like density unevenness of the liquid discharged portion between a first liquid discharge and a second liquid discharge detected by the image sensor, the second liquid discharge being a liquid discharge immediately after the first liquid discharge.

### Claim 2 (depends on 1)

The liquid discharge apparatus according to claim 1, wherein the image sensor is mounted on the carriage and is arranged in parallel with the liquid discharge head.

### Claim 3 (depends on 1)

The liquid discharge apparatus according to claim 1, wherein a reading portion of the image sensor is arranged at a head end portion in the sub-scanning direction.

### Claim 4 (depends on 1)

The liquid discharge apparatus according to claim 1, wherein the hardware processor halts discharge of liquid from one or more nozzle channels at an end of the liquid discharge head, depending on thickness of detected stripe-like density unevenness.

### Claim 5 (depends on 1)

The liquid discharge apparatus according to claim 1, wherein the hardware processor assigns no data to one or more nozzle channels at an end of the liquid discharge head, depending on thickness of detected stripe-like density unevenness.

### Claim 6 (depends on 1)

The liquid discharge apparatus according to claim 1, wherein the image sensor is configured to image the liquid discharged portion on the medium on an outward path and a return path of the liquid discharge head.

### Claim 7

A control method implemented by a computer as a liquid discharge apparatus including a hardware processor to scan a carriage having a liquid discharge head in a main-scanning direction and control discharge of liquid from the liquid discharge head, a roller rotated by a motor to convey a medium in a sub-scanning direction, and an image sensor to image a liquid discharged portion, the control method comprising:
acquiring an imaging result of the image sensor; and
shifting channels of the liquid discharge head on which discharge of liquid is valid, depending on a thickness of a stripe-like density unevenness of the liquid discharged portion between a first liquid discharge and a second liquid discharge detected by the image sensor, the second liquid discharge being a liquid discharge immediately after the first liquid discharge.

### Claim 8 (depends on 7)

The liquid discharge apparatus according to claim 7, wherein the image sensor is configured to image the liquid discharged portion on an outward path and a return path of the liquid discharge head.

### Claim 9

A non-transitory computer-readable recording medium on which an executable program is recorded, the program being executed by a computer as a liquid discharge apparatus including a hardware processor to scan a carriage having a liquid discharge head in a main-scanning direction and control discharge of liquid from the liquid discharge head, a roller rotated by a motor to convey a medium in a sub-scanning direction, and an image sensor to image a liquid discharged portion, the program instructing the computer to:
acquire an imaging result of the image sensor; and
shift channels of the liquid discharge head on which discharge of liquid is valid, depending on a thickness of a stripe-like density unevenness of the liquid discharged portion between a first liquid discharge and a second liquid discharge detected by the image sensor, the second liquid discharge being a liquid discharge immediately after the first liquid discharge.

### Claim 10 (depends on 9)

The liquid discharge apparatus according to claim 9, wherein the image sensor is configured to image the liquid discharged portion of the liquid discharge head on an outward path and a return path.