Inkjet recording method and inkjet recording apparatus

Abstract

The inkjet recording apparatus has a recording head including: large nozzles which eject ink containing pigment particles serving as a coloring material; small nozzles which eject the ink; and a common ink flow channel which is connected to the large nozzles and the small nozzles, wherein: a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles; the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium; of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; and an ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that number of ejections of the ink from the large nozzles is greater than number of ejections of the ink from the small nozzles.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

The nature of this invention, as well as other objects and advantages thereof, will be explained in the following with reference to the accompanying drawings, in which like reference characters designate the same or similar parts throughout the figures and wherein:

FIG. 1 is a general compositional diagram showing the principal part of an inkjet recording apparatus of one embodiment relating to the present invention;

FIGS. 2A and 2B are plan diagrams of recording heads; wherein FIG. 2A illustrates an example of a recording head in a case of recording in one direction only, and FIG. 2B illustrates an example of a recording head in a case of recording in two directions;

FIGS. 3A and 3B are plan diagrams showing examples of a nozzle arrangement of the recording head shown in FIG. 2A; wherein FIG. 3A shows a head where large nozzles and small nozzles are disposed respectively in rows; and FIG. 3B shows a head where large nozzles and small nozzles are disposed alternatively in the same row;

FIG. 4A is a cross-sectional diagram of a head and FIG. 4B is a cross-sectional diagram of a large nozzle, a small nozzle, and a common liquid chamber;

FIG. 5 is an approximate compositional diagram showing an ink supply system in the inkjet recording apparatus according to an embodiment of the present invention;

FIG. 6 is a partial block diagram showing the system composition of an inkjet recording apparatus according to an embodiment of the present invention;

FIG. 7 is a flowchart showing preliminary ejection control under which actions of the inkjet recording apparatus according to an embodiment of the present invention are carried out;

FIG. 8 is a flowchart showing a further example of preliminary ejection control under which actions of the inkjet recording apparatus according to an embodiment of the present invention are carried out;

FIG. 9 is an illustrative diagram showing the results of evaluation experiments using a pigment-based ink;

FIG. 10 is a general compositional diagram showing the principal part of a further inkjet recording apparatus of an embodiment relating to the present invention;

FIG. 11 is a partial block diagram showing the system composition of an inkjet recording apparatus according to an embodiment of the present invention;

FIG. 12 is an illustrative diagram showing the results of evaluation experiments using a pigment-based ink;

FIG. 13 is a further illustrative diagram showing the results of evaluation experiments using a pigment-based ink;

FIG. 14 is a flowchart showing preliminary ejection control in a case of a relatively large pigment particle size, which illustrates actions of the inkjet recording apparatus according to an embodiment of the present invention; and

FIG. 15 is a flowchart showing preliminary ejection control in a case of a very fine pigment particle size, which illustrates actions of the inkjet recording apparatus according to an embodiment of the present invention.

Claims

1. An inkjet recording apparatus comprising a recording head including: large nozzles which eject ink containing pigment particles serving as a coloring material;small nozzles which eject the ink; anda common ink flow channel which is connected to the large nozzles and the small nozzles, wherein:a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium;of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; andan ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that number of ejections of the ink from the large nozzles is greater than number of ejections of the ink from the small nozzles.

2. An inkjet recording apparatus comprising a recording head including: large nozzles which eject ink containing pigment particles serving as a coloring material;small nozzles which eject the ink; anda common ink flow channel which is connected to the large nozzles and the small nozzles, wherein:a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium;of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; andan ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that the large nozzles eject the ink that is unrelated to the image recording before the small nozzles eject the ink that is unrelated to the image recording.

3. An inkjet recording apparatus comprising a recording head including: large nozzles which eject ink containing pigment particles serving as a coloring material;small nozzles which eject the ink; anda common ink flow channel which is connected to the large nozzles and the small nozzles, wherein:a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium;of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; andan ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that a frequency of ejections of the ink from the large nozzles is higher than a frequency of ejections of the ink from the small nozzles.

4. The inkjet recording apparatus as defined in claim 1, further comprising a suctioning device which is provided at a particular position outside the region for the image recording and forcibly suctions the ink inside the recording head, wherein, after the suctioning device suctions the ink inside the recording head, the large nozzles and the small nozzles eject the ink that is unrelated to the image recording.

5. The inkjet recording apparatus as defined in claim 2, further comprising a suctioning device which is provided at a particular position outside the region for the image recording and forcibly suctions the ink inside the recording head, wherein, after the suctioning device suctions the ink inside the recording head, the large nozzles and the small nozzles eject the ink that is unrelated to the image recording.

6. The inkjet recording apparatus as defined in claim 3, further comprising a suctioning device which is provided at a particular position outside the region for the image recording and forcibly suctions the ink inside the recording head, wherein, after the suctioning device suctions the ink inside the recording head, the large nozzles and the small nozzles eject the ink that is unrelated to the image recording.

7. An inkjet recording method comprising the step of moving a recording head including large nozzles which eject ink containing pigment particles serving as a coloring material, small nozzles which eject the ink, and a common ink flow channel which is connected to the large nozzles and the small nozzles, wherein: a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium;of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; andan ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that number of ejections of the ink from the large nozzles is greater than number of ejections of the ink from the small nozzles.

8. An inkjet recording method comprising the step of moving a recording head including large nozzles which eject ink containing pigment particles serving as a coloring material, small nozzles which eject the ink, and a common ink flow channel which is connected to the large nozzles and the small nozzles, wherein: a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium;of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; andan ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that the large nozzles eject the ink that is unrelated to the image recording before the small nozzles eject the ink that is unrelated to the image recording.

9. An inkjet recording method comprising the step of moving a recording head including large nozzles which eject ink containing pigment particles serving as a coloring material, small nozzles which eject the ink, and a common ink flow channel which is connected to the large nozzles and the small nozzles, wherein: a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium;of the pigment particles which are dispersed in the ink, the pigment particles having a particle diameter not less than 150 nm account for not more than 5 volume percent; andan ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording in such a manner that a frequency of ejections of the ink from the large nozzles is higher than a frequency of ejections of the ink from the small nozzles.

10. The inkjet recording method as defined in claim 7, wherein, after the ink inside the recording head is suctioned forcibly at a particular position outside the region for the image recording, the large nozzles and the small nozzles eject the ink that is unrelated to the image recording.

11. The inkjet recording method as defined in claim 8, wherein, after the ink inside the recording head is suctioned forcibly at a particular position outside the region for the image recording, the large nozzles and the small nozzles eject the ink that is unrelated to the image recording.

12. The inkjet recording method as defined in claim 9, wherein, after the ink inside the recording head is suctioned forcibly at a particular position outside the region for the image recording, the large nozzles and the small nozzles eject the ink that is unrelated to the image recording.

13. An inkjet recording apparatus comprising: a recording head including large nozzles which eject ink containing pigment particles serving as a coloring material, small nozzles which eject the ink, and a common ink flow channel which is connected to the large nozzles and the small nozzles; andan ink type determination unit which determines a type of the ink, wherein:a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium; andwhen an ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording, ejections of the ink from the large nozzles and ejections of the ink from the small nozzles are controlled in such a manner that at least one of number of ejections of the ink from the large nozzles, number of ejections of the ink from the small nozzles, sequence of the ejections of the ink from the large nozzles and the small nozzles, and a frequency of the ejections of the ink from the large nozzles and the small nozzles is adjusted in accordance with the type of the ink determined by the ink type determination unit.

14. The inkjet recording apparatus as defined in claim 13, wherein: the type of the ink determined by the ink type determination unit is categorized according to particle size distribution of the pigment particles which are contained in the ink and serve as a coloring material; andwhen the ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at the particular timing in the process of the image recording and at the particular position outside the region for the image recording, at least one of the number of ejections of the ink from the large nozzles, the number of ejections of the ink from the small nozzles, the sequence of the ejections of the ink from the large nozzles and the small nozzles, and the frequency of the ejections of the ink from the large nozzles and the small nozzles is adjusted in accordance with the particle size distribution of the pigment particles.

15. The inkjet recording apparatus as defined in claim 13, wherein, when the ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at the particular timing in the process of the image recording and at the particular position outside the region for the image recording, in a case where the pigment particles having a particle diameter of not less than 110 nm account for not more than 5 volume percent of the pigment particles dispersed in the ink, the ejections of the ink from the large nozzles and the ejections of the ink from the small nozzles are performed simultaneously, andin a case where the pigment particles having a particle diameter of not less than 110 nm account for more than 5 volume percent of the pigment particles dispersed in the ink and the pigment particles having a particle diameter of not less than 150 nm is not more than 5 volume percent of the pigment particles dispersed in the ink, the ejections of the ink from the large nozzles and the ejections of the ink from the small nozzles are controlled in accordance with at least one of following manners:a manner in which the number of ejections of the ink from the large nozzles is greater than the number of ejections of the ink from the small nozzles;a manner in which the large nozzles eject the ink that is unrelated to the image recording before the small nozzles eject the ink that is unrelated to the image recording; anda manner in which the frequency of ejections of the ink from the large nozzles is higher than the frequency of ejections of the ink from the small nozzles.

16. An inkjet recording method comprising the step of moving a recording head including large nozzles which eject ink containing pigment particles serving as a coloring material, small nozzles which eject the ink, and a common ink flow channel which is connected to the large nozzles and the small nozzles, wherein: a volume of the ink ejected from each of the large nozzles is different from a volume of the ink ejected from each of the small nozzles;the large nozzles and the small nozzles eject the ink to perform image recording on a recording medium in terms of one direction or both directions while the recording head is moved bi-directionally in a direction substantially perpendicular to a conveyance direction of the recording medium; andwhen an ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at a particular timing in a process of the image recording and at a particular position outside a region for the image recording, a type of the ink determined is determined and ejections of the ink from the large nozzles and ejections of the ink from the small nozzles are controlled in such a manner that at least one of number of ejections of the ink from the large nozzles, number of ejections of the ink from the small nozzles, sequence of the ejections of the ink from the large nozzles and the small nozzles, and a frequency of the ejections of the ink from the large nozzles and the small nozzles is adjusted in accordance with the determined type of the ink.

17. The inkjet recording method as defined in claim 16, wherein: the type of the ink is categorized according to particle size distribution of the pigment particles which are contained in the ink and serve as a coloring material; andwhen the ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at the particular timing in the process of the image recording and at the particular position outside the region for the image recording, at least one of the number of ejections of the ink from the large nozzles, the number of ejections of the ink from the small nozzles, the sequence of the ejections of the ink from the large nozzles and the small nozzles, and the frequency of the ejections of the ink from the large nozzles and the small nozzles is adjusted in accordance with the particle size distribution of the pigment particles.

18. The inkjet recording method as defined in claim 16, wherein, when the ink ejection process in which the large nozzles and the small nozzles eject the ink that is unrelated to the image recording is performed at the particular timing in the process of the image recording and at the particular position outside the region for the image recording, in a case where the pigment particles having a particle diameter of not less than 110 nm account for not more than 5 volume percent of the pigment particles dispersed in the ink, the ejections of the ink from the large nozzles and the ejections of the ink from the small nozzles are performed simultaneously, andin a case where the pigment particles having a particle diameter of not less than 110 nm account for more than 5 volume percent of the pigment particles dispersed in the ink and the pigment particles having a particle diameter of not less than 150 nm is not more than 5 volume percent of the pigment particles dispersed in the ink, the ejections of the ink from the large nozzles and the ejections of the ink from the small nozzles are controlled in accordance with at least one of following manners:a manner in which the number of ejections of the ink from the large nozzles is greater than the number of ejections of the ink from the small nozzles;a manner in which the large nozzles eject the ink that is unrelated to the image recording before the small nozzles eject the ink that is unrelated to the image recording; anda manner in which the frequency of ejections of the ink from the large nozzles is higher than the frequency of ejections of the ink from the small nozzles.