Screen Holdings Co., Ltd.

Ricoh Company, Ltd.

Tomoyasu Okushima

Seiya Nomura

Kunio Muraji

Susumu Takahashi

Osamu Morizono

Ippei Matsumoto

Yuta Ikeda

Takaharu Yamamoto

Asuka Muramatsu

Yoshitomo Wada

Tomonori Yasuda

Akihiro Ogawa

Yuya Sugihara

A technique is provided that reduces the occurrence of a difference in print resolution between an upstream ejector and a downstream ejector due to expansion and contraction of a recording medium. An inkjet printing apparatus includes four heads arranged in a transport direction and four ejection controllers that control the four heads, respectively. Each ejection controller includes an ejection timing generator that generates an ejection timing signal for causing the head that is controlled to eject ink toward a target portion of a recording medium, an expansion/contraction amount estimator that estimates the amount of expansion and contraction in the target portion, and a correction information generator that outputs, to a downstream ejection controller, correction information that includes the ejection timing signal and expansion/contraction amount information indicating the amount of expansion and contraction.

Inkjet printing device and inkjet printing method

An object is to provide a technique allowing photographed data acquired by a camera to be converted properly to an image having a resolution necessary for inspection. An imaging device includes a camera, an image data output unit, and an external output signal generator. The camera outputs photographed data obtained by photographing an image on the basis of a camera output signal generated with a constant period. The image is printed on a printing medium transported in a transport direction X. The image data output unit outputs image data based on the photographed data to an inspection device. The external output signal generator generates an external output signal indicating timing of output of the image data by the image data output unit. The image data output unit calculates a weighted average of several pieces of photographed data stored in a buffer while giving respective weights responsive to a time gap between the camera output signal and the external output signal to the several pieces of photographed data.

Imaging device

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

The N candidate timings Tc (I) from the first one to the N-th one which are arranged in chronological order with an interval of the cycle Cs in accordance with the transport speed V of the printing medium WP are set. When the I-th candidate timing Tc (I) is set outside the prohibition interval Pw with the (I−1)th output timing Td (I−1) as the starting point timing, the I-th candidate timing Tc (I) is determined as the I-th output timing Td (I). On the other hand, when the I-th candidate timing Tc (I) is set within the prohibition interval Pw with the (I−1)th output timing Td (I−1) as the starting point timing, a timing after the prohibition interval Pw is determined as the I-th output timing Td (I).

Printer, printing method, and recording medium

An inkjet printing apparatus includes a head that ejects ink toward a recording medium transported by a transport unit, and an ejection controller that causes the head to eject ink. The ejection controller is configured to perform process including: process of calculating a transport speed of the recording medium; process of generating reference timing of ejection of ink by the head; process of determining a target delay amount by which timing of ejection of ink by the head is delayed from the reference timing on the basis of a transport speed coinciding with the reference timing; process of updating a target delay amount, on the occurrence of change in the transport speed before the recording medium is transported by a distance corresponding to the target delay amount, the target delay amount being updated in response to the transport speed as changed; and process of delaying timing of ejection of ink by the head on the basis of the target delay amount as updated.

Inkjet printing apparatus and inkjet printing method

A head voltage correcting method for inkjet printing apparatus which perform printing by dispensing ink droplets from a head to a printing medium. The method includes the following steps:

Head voltage correcting method for inkjet printing apparatus, and an apparatus using same

A controller controls printing heads to print a page information mark with black ink to perform line flushing. The printing heads each have a plurality of inkjet nozzles for discharging ink being disposed in parallel in a width direction of web paper. Upon printing the mark, when an overlap region is present in which a mark printable region overlaps a line flushing region with ink other than the black ink, the controller performs control to decrease an ink discharge amount per unit area in the overlap region in the mark printable region to be smaller than that in the mark printable region except for the overlap region and the line flushing region. This causes a decreased total ink discharge amount in the overlap region.

Inkjet printing method and inkjet printing apparatus

A correction value acquiring method for inkjet printing apparatus includes the following steps: a testing chart forming step for forming a testing chart in one printing job, the testing chart including a first line segment group having a plurality of first line segments formed by causing a drive circuit of a head module acting as reference to output a reference drive signal for obtaining a reference density, and a second line segment group having a plurality of second line segments formed by causing drive circuits of head modules other than the head module acting as reference to output the reference drive signal and drive signals with a plurality of different correction values added to the reference drive signal; an identifying step for identifying from the testing chart a second line segment having a density matching with that of a first line segment; and a correction value acquiring step for acquiring a correction value corresponding to the second line segment identified.

Correction value acquiring method for inkjet printing apparatus, and an inkjet printing apparatus

A rotary encoder correcting method for a transport apparatus having a rotary encoder for outputting output signals in response to rotation of a transport roller. The method includes the steps of setting beforehand the number of n-divided output signals obtained by dividing, by n, the number of output signals outputted from the rotary encoder with one rotation of the transport roller; measuring a divided area shift time for each divided area when a printing medium is transported at constant speed and each time the number of output signals agrees with the number of n-divided output signals; and calculating a correction coefficient for each divided area based on the divided area shift time. The divided area shift time is corrected for each divided area of the rotary encoder based on each correction coefficient when a process is carried out on the printing medium.

Rotary encoder correcting method for a transport apparatus, and a transport apparatus using same

A printing apparatus for performing printing under control of a head controller which receives image data, and which is connected to a print head for printing. The head controller includes an image data shaping unit for shaping the image data into print data corresponding to the print head, a sequence information generating unit for generating sequence information, based on the print data, showing operation at a time of printing by the print head, a data guarantee information adding unit for adding data guarantee information to the print data and the sequence information, for error detection based on the print data and the sequence information, a readout unit for reading print information including the print data, the sequence information, and the data guarantee information, and an information inspecting unit for inspecting propriety of the print information based on the data guarantee information and the sequence information read by the readout unit.

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Kyoto, Japan

Tomoyasu Okushima