Riso Kagaku Corporation

Ryo Terakado

Takashi Ebisawa

Mamoru Saitou

Toshihide Maesaka

Masato Hirai

Masashi Hara

Tomohiko Shimoda

Hirokazu Yabune

Yukihiro Maeda

Akihiro Yamagata

Kyosuke Watari

A paper supply device is equipped with a paper supply unit that sequentially supplies a plurality of print media, and a control unit that controls the paper supply unit. During sequential supply of a plurality of print media at a paper supply interval, in the case that it is necessary to secure a paper supply interval which is set in advance and is longer than the paper supply interval, a reference paper supply interval, based on a point in time which is a natural number multiple of the paper supply interval, and a post print process paper supply interval are compared. Print media are supplied at the post print process paper supply interval in the case that the post print process paper supply interval and the reference paper supply interval are different.

Paper supply device

A printing system, including a first printing part, a second printing part that is disposed downstream of the first printing part in the conveying direction of a medium, and a conveyance mechanism that conveys the medium The conveyance mechanism includes a passage detection sensor, a conveyor roller, and a resist roller that is disposed downstream in the conveying direction from the passage detection sensor and the conveyor roller, that is butted by the medium, and that conveys the medium slackened due to the butting. The printing system further includes a controller configured to control the conveyor roller so that the slack amount of the subsequent medium is constant based on the conveyance status of the preceding medium and the detection time of the leading edge of the subsequent medium detected by the passage detection sensor.

Printing system

A controller performs a positioning operation by driving an elevator motor before starting a paper feed operation using a paper feed roller unit. While the controller performs the paper feed operation using the paper feed roller unit after an upper limit sensor is brought into an on-state by the positioning operation, when the upper limit sensor is brought into an off-state, the controller performs a paper feed position following operation by driving the elevator motor to raise a paper feed tray until the upper limit sensor is brought into the on-state. The controller controls the elevator motor with setting a current limit in the positioning operation such that a current flowing to the elevator motor does not exceed a predetermined current limit value and controls the elevator motor without the current limit in the paper feed position following operation.

Paper feed device

A paper supply apparatus includes: a primary paper supply roller that feeds out and conveys a print medium from a paper tray on which the print medium is placed; resist rollers that a leading end of the print medium abuts to form a flexure in the print medium by temporarily ceasing conveyance, and rotate at a predetermined timing after this flexure is formed, to convey the print medium toward a conveyance mechanism; and a control unit that executes assist control that drives the primary paper supply roller during the time that the print medium is being conveyed by the resist rollers to assist conveyance of the print medium by the resist rollers. The control unit executes the assist control such that the flexure in the print medium remains at a point in time at which the leading end of the print medium reaches the conveyance mechanism.

Paper supply 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.

An inkjet image forming apparatus includes print heads, a first tank, an ink circulation line, and a controller. The ink circulation line includes an ink supply line for supplying ink from the first tank to the print heads, and an ink return line for returning ink collected from the print heads to a second tank. The controller controls line elements of the ink circulation line, to adjust a magnitude relation between a first product and a second product, in accordance with the type of ink. The first product is a product of factors including a flow passage length along, a viscosity of ink in, and a fluid resistance coefficient of the ink supply line. The second product is a product of factors including a flow passage length along, a viscosity of ink in, and a fluid resistance coefficient of the ink return line.

Inkjet image forming apparatus

A print head includes an ink chamber for storing ink therein, an ink propelling mechanism for propelling ink out of the ink chamber, and a temperature sensor for measuring an ink temperature in the ink chamber, an ink circulation route has a route including the ink chamber, and a print controller works at least along deactivation of an energy saving mode or upon power-on, in response to the temperature sensor having a measure of ink temperature lower than a prescribed value, for a pre-treatment to have the ink propelling mechanism make ink vibrating actions within degrees not to cause ink to be propelled out of the ink chamber, until the ink temperature becomes the prescribed value or more.

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Ibaraki, Japan

Ryo Terakado