Screen Holdings Co., Ltd.

Tomonori Yasuda

Tomoyasu Okushima

Kiyoomi Mitsuki

Akira Murata

Takanori Tsuji

Akihiro Ogawa

A technique for making the amount of ink to be calculated appropriate in accordance with the amount of ink to be ejected from heads is provided. An inkjet printing apparatus includes a supply tank, a return tank, a first connecting pipe, a second connecting pipe, a head, a pressure-difference producer, an ejection-amount predictor, and a pressure controller. The first connecting pipe transfers ink in the supply tank to the return tank. The second connecting pipe returns ink in the return tank to the supply tank. The head is interposed in the first connecting pipe. The pressure-difference producer sends ink from the supply tank to the return tank through the first connecting pipe. The ejection-amount predictor predicts the amount of ink to be ejected at a time to come after the present time from the head. The pressure controller controls the amount of ink to be supplied from the supply tank to the head, by controlling the pressure-difference producer in accordance with the predicted amount of ink to be ejected.

Ink circulation system and inkjet printing apparatus

To provide an inkjet printing apparatus capable of continuing printing even during speed change of web paper WP, a transport controller of this invention controls drive rollers, and to make constant at each point of time during the speed change of the drive rollers, a speed difference which is a difference between a first speed which is a transporting speed of web paper when the upstream nozzle dispenses an ink droplet and a second speed which is a transporting speed of web paper when a downstream nozzle dispenses an ink droplet. In this way, a constant relationship is realized, at each point of time during the speed change of drive rollers, between a landing position on the web paper of the ink droplet relating to the upstream nozzle and a landing position on the web paper of the ink droplet relating to the downstream nozzle.

Inkjet printing apparatus

An ink-jet printing device according to the present invention includes: first and second nozzles each configured to discharge ink droplets onto a recording medium being conveyed; a calculation unit to calculate a landing position difference on the recording medium being conveyed at a conveyance speed based on first and second conveyance speeds and first and second landing position differences; and a timing control unit to control each of timings of ink droplet discharge from the first and second nozzles based on the landing position difference calculated by the calculation unit. This configuration allows appropriate correction of variance in the landing positions of ink droplets discharged from the nozzles.

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Kyoto, Japan

Tomonori Yasuda