Inkjet printing apparatus and ejecting method

1. An inkjet printing apparatus comprising:

a print head having an ejection opening surface on which a first ejection opening array capable of ejecting a first ink to a print medium and a second ejection opening array capable of ejecting a second ink to a print medium are arranged;

a cap member configured to cap the first ejection opening array and the second ejection opening array; and

a print controller configured to:

(i) perform a first preliminary ejecting operation for preliminarily ejecting the first ink to the cap member in a state in which a position of the cap member relative to the print head corresponds to a first relative position;

(ii) move relatively at least one of the print head and the cap member to a second relative position;

(iii) perform a second preliminary ejecting operation for preliminarily ejecting the second ink to the cap member in a state in which a position of the cap member relative to the print head corresponds to the second relative position, the second relative position being a position in which the second ink ejected during the second preliminary ejecting operation lands in a position that overlaps with an area where the first ink ejected during the first preliminary ejecting operation lands; and

(iv) perform a third preliminary ejecting operation for preliminarily ejecting the first ink to the cap member after the second preliminary ejecting operation in a state in which a position of the cap member relative to the print head corresponds to the first relative position.

2. The inkjet printing apparatus according to claim 1 , wherein the first ink is color ink and the second ink is black ink.

3. The inkjet printing apparatus according to claim 1 , wherein the second ink is an ink that easily accumulates compared to the first ink.

4. The inkjet printing apparatus according to claim 1 , wherein a second preliminary ejection amount in the second preliminary ejecting operation is less than a total of a first preliminary ejection amount in the first preliminary ejecting operation and a third preliminary ejection amount in the third preliminary ejecting operation.

5. The inkjet printing apparatus according to claim 4 , wherein the first preliminary ejection amount is greater than the third preliminary ejection amount.

6. The inkjet printing apparatus according to claim 1 , further comprising a wiping member for wiping the ejection opening surface of the print head,

wherein the print controller performs first preliminary ejecting operation, the second preliminary ejecting operation and the third preliminary ejecting operation after the ejection opening surface is wiped by the wiping member.

7. The inkjet printing apparatus according to claim 1 , further comprising:

an ink tank for accommodating ink supplied to the print head; and

a circulation unit configured to circulate ink through a circulation path including the ink tank and the print head; and

a wiping member for wiping the ejection opening surface of the print head while suspending ink circulation by the circulation unit,

wherein the print controller performs the first preliminary ejecting operation, the second preliminary ejecting operation and the third preliminary ejecting operation after the ejection opening surface is wiped by the wiping member, and the circulation unit starts the ink circulation after the third preliminary ejecting operation is performed.

8. The inkjet printing apparatus according to claim 7 , wherein the print controller performs the second preliminary ejecting operation by using ejection openings other than an ejection opening located at an end of the second ejection opening array.

9. The inkjet printing apparatus according to claim 7 , wherein the print controller performs the second preliminary ejecting operation by using ejection openings located near a center of the second ejection opening array.

10. The inkjet printing apparatus according to claim 7 , wherein the first ejection opening array and the second ejection opening array are displaced from each other by a predetermined distance in a second direction perpendicular to a first direction, the first direction being a direction in which the relative position is changed.

11. The inkjet printing apparatus according to claim 7 , wherein the first ejection opening array and the second ejection opening array have different lengths in a second direction perpendicular to a first direction, the first direction being a direction in which the relative position is changed.

12. The inkjet printing apparatus according to claim 7 , wherein

the print head has a plurality of ejection modules, each having ejection opening arrays including the first ejection opening array and the second ejection opening array extending in a direction with a predetermined angle with respect to a second direction perpendicular to a first direction, the first direction being a direction in which the relative position is changed, the plurality of ejection modules being arranged in the second direction, and

an end of the ejection opening arrays of the ejection module has an area overlapping with the ejection opening arrays of an adjacent ejection module in the second direction.

13. The inkjet printing apparatus according to claim 1 , further comprising a moving unit configured to move the cap member relative to the print head.

14. An ejecting method in an inkjet printing apparatus that includes a print head having an ejection opening surface on which a first ejection opening array capable of ejecting a first ink to a print medium and a second ejection opening array capable of ejecting a second ink to a print medium are arranged; and a cap member configured to cap the first ejection opening array and the second ejection opening array, the ejecting method comprising:

performing a first preliminary ejecting operation for preliminarily ejecting the first ink to the cap member in a state in which a position of the cap member relative to the print head corresponds to a first relative position,

moving relatively at least one of the print head and the cap member to a second relative position;

performing a second preliminary ejecting operation for preliminarily ejecting the second ink after the first preliminary ejecting operation in a state in which a position of the cap member relative to the print head corresponds to the second relative position, the second relative position being a position in which the second ink ejected during the second preliminary ejecting operation lands in a position that overlaps with an area where the first ink ejected during the first preliminary ejecting operation lands; and

performing a third preliminary ejecting operation for preliminarily ejecting the first ink to the cap member after the second preliminary ejecting operation in a state in which a position of the cap member relative to the print head corresponds to the first relative position.

15. The inkjet printing apparatus according to claim 1 , wherein the first ejection opening array and the second ejection opening array are arranged in an area corresponding to a width of a print medium.