# US 12,179,497 B2 · Image forming apparatus

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,179,497 B2
- Document ID: US12179497B2
- Status: Granted
- Kind: B2
- Application number: 17/969,367
- Filed: 2022-10-19
- Published: 2023-04-27
- Granted: 2024-12-31
- Earliest claimed: 2021-10-26
- Assignees: KYOCERA Document Solutions Inc.
- Applicants: KYOCERA Document Solutions Inc.
- Inventors: Yuzuru Yuasa
- Web page: https://patentgrep.com/patent/US12179497B2

## CPC

- B41J 2/2142: {Detection of malfunctioning nozzles (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045, B41J2/05; jet deflection sensors B41J2/125; for cleaning purposes B41J2/16579)}
- B41J 2/2139: {Compensation for malfunctioning nozzles creating dot place or dot size errors (generating single droplets or particles on demand by pressure, e.g. electromechanical transducers B41J2/045)}
- B41J 2/2146: {for line print heads}
- G06K 15/02: using printers
- 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 control unit determines nozzles corresponding to the image to be printed and causes a recording head to eject ink from the nozzles. A correction processing unit performs a correction process corresponding to each of ink ejection malfunction positions in the image. The correction processing unit (a) prints a test pattern using the recording head, (b) determines the ink ejection malfunction positions on the basis of a scanned image of the test pattern, (c) determines a droplet hit position deviation amount of the ink at each of the ink ejection malfunction positions, and (d) determines a print sheet type of the print sheet, performs comparison between the droplet hit position deviation amount and a threshold value set for the print sheet type, and determines whether the correction process should be performed to the ink ejection malfunction position or not on the basis of a result of the comparison.

## Claims

### Claim 1

An image forming apparatus, comprising:
a recording head configured to eject ink corresponding to an image to be printed, using arranged nozzles;
a control unit configured to determine nozzles corresponding to the image to be printed, correspondingly to a position of a print sheet, and cause the recording head to eject ink from the nozzles; and
a correction processing unit configured to perform a correction process corresponding to each of plural ink ejection malfunction positions in the image;
wherein the correction processing unit (a) prints a test pattern comprising of vertical thin lines wherein each line corresponds to each arranged nozzle using the recording head, (b) determines the ink ejection malfunction positions on the basis of a scanned image of the test pattern, (c) determines a droplet hit position deviation amount of the ink at each of the ink ejection malfunction positions by measuring a deviation amount of a density detection position based on density detection positions in the scanned image of the vertical thin line in the test pattern and multiplying the measured deviation amount of the density detection position by a predetermined coefficient, and (d) determines a print sheet type of the print sheet, performs comparison between the droplet hit position deviation amount and a threshold value set for the print sheet type, and determines whether the correction process should be performed to the ink ejection malfunction position or not on the basis of a result of the comparison.

### Claim 2 (depends on 1)

The image forming apparatus according to claim 1, wherein the threshold value of an impermeable sheet type as the print sheet type is set to be lower than the threshold value of a permeable sheet type as the print sheet type.

### Claim 3 (depends on 2)

The image forming apparatus according to claim 2, wherein the correction processing unit prints the test pattern using the recording head on the print sheet of the impermeable sheet type.

### Claim 4 (depends on 1)

The image forming apparatus according to claim 1, wherein the correction processing unit performs the correction process as a hardware process.

### Claim 5 (depends on 1)

The image forming apparatus according to claim 1, further comprising a line sensor configured to detect a position of the print sheet;
wherein the line sensor generates the scanned image of the test pattern.