Abstract: A printing apparatus and a preliminary discharge control method capable of efficient preliminary discharge control even in a case where a time interval to assure normal printing is equal or nearly equal to the period of one print scanning of an inkjet printhead. In the method, in an inkjet printhead which performs printing by discharging ink from plural print elements while reciprocate-scanned by a carriage, the number of ink dischargings from each of the plural print elements is counted during print scanning by reciprocate scanning. It is determined whether or not the counted number of ink dischargings from each of the plural print elements is equal to or greater than a predetermined number at predetermined intervals. In accordance with the result of determination, a printable period is updated, and the updated printable period is compared with time necessary for the next print scanning upon completion of one print scanning by reciprocate scanning.

Abstract: The present invention provides an ink jet printing apparatus that can inexpensively print desired colors without causing ink color mixture. In a print head, a plurality of nozzle rows for respective ink colors are arranged in parallel with one another. Arrangements and driving control are provided so that few mists resulting from an ink ejecting operation move so as not to reach the print head or fall.

Abstract: An inkjet recording apparatus suppresses defective ejection while reducing a consumed ink amount. In the apparatus, a cap-open period, during which a cap member does not cap ejection ports of a recording head of the apparatus, is measured, and a recovery operation executed by a recovery unit is controlled based on a cumulated cap-open period. With the above arrangement, there can be solved a problem that the ink ejecting state of the recording head is deteriorated depending on a recording operation because a cap-open state, in which the cap member does not cap the ejection ports of the recording head, continues while the inkjet recording apparatus executes the recording operation, thereby the reliability of the inkjet recording apparatus can be improved.

Abstract: A liquid ejection head according to the present invention includes a single liquid supplying port to which a liquid is supplied, a plurality of liquid supplying passages having one end in communication with the liquid supplying port, a plurality of common liquid chambers that are in communication with the other ends of the liquid supplying passages, respectively, and a plurality of ejection port groups which are in communication with the common liquid chambers via liquid channels and from which liquid droplets are ejected. A cross sectional area or length of the liquid supplying passage in communication with the ejection port group having a larger sum of opening areas of the ejection ports is set smaller than that of the liquid supplying passage that is in communication with the ejection port group having a smaller sum of opening areas of the ejection ports.

Abstract: In an ink jet print head used in a serial type ink jet printing apparatus according the present invention, a portion of the nozzle column is given a wider nozzle-to-nozzle interval than those of other portions of the nozzle column so that the width in the line feed direction of each image area printed in a single printing scan by the ink jet print head is longer than a distance that a print medium is moved by one line feed. In this serial print head, the width of each image area printed by a single printing scan can be made a predetermined amount longer than the line feed distance at all times. As a result, the adjoining image areas printed by separate printing scans overlap each other at their boundary portions by a predetermined amount.

Abstract: A liquid ejection head according to the present invention includes a single liquid supplying port to which a liquid is supplied, a plurality of liquid supplying passages having one end in communication with the liquid supplying port, a plurality of common liquid chambers that are in communication with the other ends of the liquid supplying passages, respectively, and a plurality of ejection port groups which are in communication with the common liquid chambers via liquid channels and from which liquid droplets are ejected. A cross sectional area or length of the liquid supplying passage in communication with the ejection port group having a larger sum of opening areas of the ejection ports is set smaller than that of the liquid supplying passage that is in communication with the ejection port group having a smaller sum of opening areas of the ejection ports.