Riso Kagaku Corporation

Mamoru Saitou

Takashi Ebisawa

Ryo Terakado

Toshihide Maesaka

Included are: a storage unit configured to store profile data in which the amount of landing deviation and the ejection frequency representing the number of ejections of ink droplets per unit time are associated with each other; a correction judgment unit configured to determine whether to allow ejection timing control in print processing by selecting 30 dots as a unit line in an image, adding up a total volume of ink ejected to the unit line, and comparing the total volume of ejected ink with a predetermined threshold; and an ejection control unit configured to obtain the ejection frequency for ejecting ink at a predetermined time interval, from the total volume of ink ejected in the unit line, calculate the amount of landing deviation from the ejection frequency, and control the ejection timing in accordance with the calculated amount of landing deviation.

Image formation apparatus

An inkjet printer includes nozzle rows aligned along a printing direction along which printing on a print medium is executed, and a controller configured to control ejection of the ink droplets from the nozzle rows. The nozzle rows include a pair of an upstream nozzle row and a downstream nozzle row. The upstream nozzle row is positioned just upstream from the downstream nozzle row along the printing direction. The controller controls ejection of the ink droplets from the upstream nozzle row and the downstream nozzle row so that propulsive forces applied to ink droplets ejected from the downstream nozzle row are made larger, based on image data associated with the upstream nozzle row, than propulsive forces applied to ink droplets ejected from the upstream nozzle row. The inkjet printer can restrict degradation of print quality by landing the ink droplets ejected from the downstream nozzle at their target positions.

Inkjet printer

An image forming apparatus includes at least one inkjet head which is disposed above a feed path of a print medium and on which plural nozzles are aligned along a primary sweeping direction perpendicular to a feed direction of the print medium fed along the feed path. The image forming apparatus forms images by ejecting ink droplets from the nozzles. The image forming apparatus includes a controller that is operable to compensate ejection timings of ink droplets to be ejected from the nozzles onto the print medium based on ejection density of the ink droplets. The image forming apparatus can form good images that are not affected by ink dot displacements caused by feed airflow even when the ink dot displacements are affected by self-induced airflow.

Image forming apparatus

An image forming apparatus includes a controller configured to adjust ink ejection amounts from nozzles in a downstream nozzle array on a basis of a bypassing air flow degree. The bypassing air flow degree is calculated based on an ejection density of ink ejected from nozzles in an upstream nozzle array on a recording medium and indicates a generation degree of a bypassing air flow generated when a transfer air flow generated by transfer of the recording medium bypasses a self-generated air flow generated by ink ejected from the nozzles in the upstream nozzle array. The downstream nozzle array is a nozzle array located downstream in a transfer direction among a plurality of nozzle arrays. The upstream nozzle array is a nozzle array located upstream in the transfer direction among the plurality of nozzle arrays.

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Ibaraki-ken, Japan

Mamoru Saitou