Inkjet recording apparatus

An inkjet recording apparatus comprising:

• an ink receiver configured to receive ink ejected in a preliminary ink ejection process that is executed to maintain and recover ink ejection performance of a recording head that is configured to eject ink in a vertically or obliquely upward direction against a direction of gravity to record an image on a medium, the ink receiver comprising:
• an opening that acts as an inlet for the ink ejected into said ink receiver;
• and
• a ceiling surface that, at least during the preliminary ink ejection process, faces an ink ejecting portion of the recording head, said ceiling surface being configured to stop the ink ejected into said ink receiver and to direct the ink away to prevent leaking from said opening to the outside of said ink receiver,
• wherein, at least during the preliminary ink ejection process, a distance d from the ink ejecting portion to said ceiling surface satisfies the following inequality:
• d < m ⁢ ⁢ v o 6 ⁢ ⁢ π ⁢ ⁢ η ⁢ 3 ⁢ ⁢ m 4 ⁢ ⁢ πρ 3
• where m represents a mass of an ink droplet ejected from the recording head, ν0 represents an ejection velocity of the ink droplet, ρ represents a density of the ink droplet, and η represents a viscosity resistance of air, and values employed for d, m, ν0, ρ and η are all expressed in units of the same system of measurement.

An inkjet recording apparatus comprising:

• an ink receiving means for receiving ink ejected in a preliminary ink ejection process that is executed to maintain and recover ink ejection performance of a recording head that is configured to eject ink in a vertically or obliquely upward direction against a direction of gravity to record an image on a medium, the ink receiver comprising:
• an inlet means for allowing entry of the ink ejected into said ink receiver;
• and
• an ink leakage prevention means for preventing the ink ejected into said ink receiver from leaking from said inlet means,
• wherein said ink leakage prevention means comprises a ceiling surface that, at least during the preliminary ink ejection process, faces an ink ejecting portion of the recording head, with a distance d from the ink ejecting portion to said ceiling surface satisfying the following inequality:
• d < m ⁢ ⁢ v o 6 ⁢ ⁢ π ⁢ ⁢ η ⁢ 3 ⁢ ⁢ m 4 ⁢ ⁢ πρ 3
• where m represents a mass of an ink droplet ejected from the recording head, ν0 represents an ejection velocity of the ink droplet, ρ represents a density of the ink droplet, and η represents a viscosity resistance of air, and values employed for d, m, ν0, ρ and η are all expressed in units of the same system of measurement.