Inkjet recording apparatus for recording images by ejecting ink on recording media

Patent metadata

Field	Value
Publication number	US-11413872-B2
Application number	US-202017067707-A
Country	US
Kind code	B2
Filing date	Oct 11, 2020
Priority date	Oct 11, 2019
Publication date	Aug 16, 2022
Grant date	Aug 16, 2022

Abstract

Provided is an inkjet recording apparatus that reduces excessive or insufficient flushing of each of the nozzles by appropriately controlling the ink ejection amount in the next flushing for each nozzle based on the actual ink ejection state of each of the nozzles of a recording head during image formation. A control unit causes the recording head to execute flushing for ejecting the ink at a timing different from a timing that contributes to image formation on the recording medium. A conveyor belt has opening portions for allowing ink ejected from each of the nozzles of the recording head during flushing to pass. The control unit controls the ink ejection amount for each of the nozzles during the next flushing based on an integrated printing rate for each of the nozzles after the recording head has performed the previous flushing.

First claim

What is claimed is:

1. An inkjet recording apparatus comprising:
a recording head having a plurality of nozzles that eject ink; and
an endless conveyor belt that conveys a recording medium to a position facing the recording head; and
a control unit that causes the recording head to execute flushing for ejecting the ink at a timing different from a timing that contributes to image formation on the recording medium; wherein
the conveyor belt has opening portions for allowing the ink ejected from each nozzle of the recording head at the time of the flushing to pass;
the control unit controls an ink ejection amount in a next flushing for each of the nozzles based on an integrated printing rate for each of the nozzles after the recording head performs a previous flushing;
the conveyor belt has a plurality of opening portion groups in a conveying direction of the recording medium, in which the opening portions are arranged in a belt width direction perpendicular to a conveying direction of the recording medium;
the inkjet recording apparatus further comprises a recording medium supply unit that supplies the recording medium to the conveyor belt; and
the control unit determines a supply timing for supplying the recording medium to the conveyor belt according to the size of the recording medium so that an integer number of recording media of other sizes is conveyed during one cycle of the conveyor belt that conveys a plurality of recording media of a smallest size, and causes the recording media to be supplied from the recording medium supply unit to the conveyor belt at the determined supply timing.

2. The inkjet recording apparatus according to claim 1 , wherein
the control unit calculates the integrated printing rate for each of the nozzles based on an ink ejection duty for each of the nozzles when an image is formed on the recording medium by controlling the recording head after the recording head performs a previous flushing.

3. The inkjet recording apparatus according to claim 1 , wherein
the control unit changes the ink ejection amount in the flushing according to a usage environment.

4. The inkjet recording apparatus according to claim 3 , wherein
the usage environment includes a temperature of the environment.

5. The inkjet recording apparatus according to claim 4 , further comprising
a first temperature sensor that detects the ambient temperature; wherein
the control unit changes the ink ejection amount based on a detection result of the first temperature sensor.

6. The inkjet recording apparatus according to claim 1 , wherein
the control unit changes the ink ejection amount at the time of the flushing according to a temperature of the recording head.

7. The inkjet recording apparatus according to claim 6 , further comprising
a second temperature sensor that detects the temperature of the recording head; wherein
the control unit changes the ink ejection amount based on a detection result of the second temperature sensor.

8. The inkjet recording apparatus according to claim 1 , wherein
the control unit changes the ink ejection amount at the time of the flushing according to a type of the ink.

9. The inkjet recording apparatus according to claim 8 , wherein
the type of ink includes a color of the ink recognized based on image data of an image recorded on the recording medium.

10. The inkjet recording apparatus according to claim 1 , wherein
the control unit changes the ink ejection amount at the time of the flushing according to a size of the recording medium.

11. The inkjet recording apparatus according to claim 10 , further comprising
a storage unit that stores information about the size of the recording medium conveyed by the conveyor belt, wherein
the control unit recognizes the size of the recording medium based on the information stored in the storage unit, and changes the ink ejection amount according to the recognized size.

12. The inkjet recording apparatus according to claim 1 , wherein
the conveyor belt has a plurality of opening portion groups in a conveying direction of the recording medium, in which the opening portions are arranged in a belt width direction perpendicular to a conveying direction of the recording medium; and
the control unit, determines a pattern in one cycle of the conveyor belt for arranging the opening portion groups used at the time of flushing in the conveying direction according to the size of the recording medium, and causes the recording head to perform the flushing at a timing when the opening portion groups located in the pattern face the recording head due to the running of the conveyor belt.

13. The inkjet recording apparatus according to claim 12 , wherein
the opening portion groups are located at equal intervals in the conveying direction of the conveyor belt.

14. The inkjet recording apparatus according to claim 12 , wherein
the control unit, in addition to timing when the opening portion groups face the recording heads, causes flushing of the recording head to be executed at timing when the recording medium faces the recording heads.

15. An inkjet recording apparatus comprising:
a recording head having a plurality of nozzles that eject ink;
an endless conveyor belt that conveys a recording medium to a position facing the recording head; and
a control unit that causes the recording head to execute flushing for ejecting the ink at a timing different from a timing that contributes to image formation on the recording medium; wherein
the conveyor belt has opening portions for allowing the ink ejected from each nozzle of the recording head at the time of the flushing to pass;
the control unit controls an ink ejection amount in a next flushing for each of the nozzles based on an integrated printing rate for each of the nozzles after the recording head performs a previous flushing;
the conveyor belt has a plurality of opening portion groups in a conveying direction of the recording medium, in which the opening portions are arranged in a belt width direction perpendicular to a conveying direction of the recording medium;
the control unit determines a pattern in one cycle of the conveyor belt for arranging the opening portion groups used at the time of flushing in the conveying direction according to the size of the recording medium, and causes the recording head to perform the flushing at a timing when the opening portion groups located in the pattern face the recording head due to the running of the conveyor belt; and
the opening portion groups are irregularly located in the conveying direction in one cycle of the conveyor belt such that the interval in the conveying direction, between adjacent opening portion groups of the conveyor belt, is not constant.

Assignees

• Kyocera Document Solutions Inc

Inventors

• Maruta Masaaki

Classifications

• B41J11/007

  Conveyor belts or like feeding devices · CPC title

• B41J2/16532

  by applying vacuum only · CPC title

• B41J2/16517 Primary

  Cleaning of print head nozzles (B41J2/16505, B41J2/1707 take precedence) · CPC title

• B41J2/16526

  by applying pressure only · CPC title

• B41J2002/16573

  Cleaning process logic, e.g. for determining type or order of cleaning processes · CPC title