摘要:
In an ink jet printing apparatus using many types of inks to execute bidirectional printing, if ejection opening rows for yellow, magenta, and cyan inks are symmetrically arranged, ejection opening rows for a black ink are arranged adjacent to the most inside ejection opening rows for the yellow ink. Thus, a difference in color between forward scanning and backward scanning is determined by a difference in coloring between the black ink and the yellow ink. In this case, a possible color drift attributed to bidirectional printing can be suppressed by selecting the inks so that the difference in coloring between the black ink and the yellow ink is smaller than that between the black ink and the other color inks.
摘要:
An ink-jet printing apparatus and an ink-jet printing method allow the printing of an image with high quality without causing a change in ink color formed on the printing medium while keeping the printing conditions constant regardless of changing of the number of nozzles to be printed and the amount of transferring of the printing medium. This printing is performed, for example, by restricting use of the number of nozzles, which belong to a nozzle row located on an upstream side in the sub-scan direction, before changing the amount of transferring of the printing medium; and restricting use of the number of nozzles, which belong to the nozzle rows located on a downstream side in the sub-scan direction, after changing the amount of transferring of the printing medium.
摘要:
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.
摘要:
There is provided a printing registration method for stably performing printing registration in bi-directional scanning by a print head in a printing apparatus or printing registration between a plurality of print heads with high accuracy. In complementary printing by the bi-directional scanning by the head, a plurality of patterns are printed while printing starting timings are shifted by predetermined quantities with respect to reference dots (dots formed by forward scanning). In the pattern, an area factor defined by the dots formed by the printing is varied according to the shifting. The plurality of patterns are optically read as an average density. The timing corresponding to a point where the read average density is highest can be determined as a printing registration condition. Furthermore, an optical sensor used for the reading is located at a position where an S/N ratio is stable with respect to fluctuations in distance from the object to be read, thus achieving stable reading.
摘要:
In complementarily printing by bi-directional scannings of a head or by a plurality of print heads, first patterns and second patterns including reference dots for example, dots formed by a forward scan of the bi-directional scannings or by one of the plurality of print heads and dots each having the different direction of shifting of relative printing positions to the reference dots are printed in corresponding to the plurality of shifting amounts. These first and second patterns have the similar characteristics of a change in density. The difference is only that their characteristics in density change are inverted according to the direction of shifting. The intersection point of these two characteristics in density change is obtained as a position for adjustment where dot-formed positions match. This makes it easy to perform printing registration in a printing apparatus in the case of printing by a forward and reverse scan of a printing head or in the case of printing by means of a plurality of printing heads. In this case, operations by a user etc. are also unnecessary and are easily performed.
摘要:
In a complimentary printing by bi-directional scanning of a head or by a plurality of heads, a plurality of patterns in which a print start timing is shifted by a predetermined amount are printed with respect to a reference dot, e.g. formed by the forward scan of the bi-directional scanning or by one of the plurality heads. In these patterns, an area factor by the dots formed by printing of the patterns is designed to be varied depending upon shifting amount. An average density is read from each of the plurality of patterns, optically. The timing at which the maximum one among average densities read from the patterns is obtained, can be set as the printing registration condition. Further, a processing including a coarse adjustment to a fine adjustment is performed in a series of algorithm. By these processings, printing registration between a forward and a reverse scan of a print head or printing registration between a plurality of print heads in a printing apparatus can be performed simply and with high accuracy, without operating by a user.
摘要:
An image processor in which an under color process is performed according to a color region to which input color image data belongs. The under color process generates a plurality of color component signals including a black component signal including a black component signal, with the color region being defined by hue. Therefore, even if input color image data includes color components other than an under color component, tonality (i.e., linearity between an input color value and an output color value) is compensated for.
摘要:
In an ink-jet apparatus for forming images through use of an ink-jet head provided with a plurality of ink ejection heaters with respect to only one ejection orifice, an accurate estimation of temperature of the ink-jet head is made possible by controlling ink-ejection amount in a step-by-step manner. For this purpose, there is provided a device for counting frequency of use of the plurality of heaters within a predetermined period of time independently for each combination of the heaters for ejecting different amount of ink (in steps S1002, S1003), and a combining device for adding a correction value to each of the thus counted value on the basis of the heater driving condition, and converting the total value into the energy applied within a predetermined period (in steps S1008, S1004 and S1005). The estimation of temperature is performed by use of the thus obtained energy.
摘要:
An ink jet recording apparatus and method for recording an image on a recording medium by ejecting ink from each of a plurality of recording elements of a recording head is provided. The apparatus includes an ink ejection amount changing unit for changing an ink ejection amount of each recording element of the recording head, a timing controller for controlling an ink ejection timing of the ink ejection amount changing unit, a modulator for modulating record data, and a controller for controlling to record an image on the recording medium by outputting the record data modulated by the modulator synchronously with an ejection timing determined by the timing controller.
摘要:
In a printer, when difference in ejection characteristic among nozzles appears as density non-uniformity and the way of letting the density non-uniformity appear is different depending upon kind of image, proper density correction is performed. Specifically, the kind of image to be printed is judged, and when the kind of image is a halftone image according to the judgment, a density correction table corresponding to the halftone image is selected and used to perform the density correction. Also when the kind of image is judged to be a solid image (without a portion of the halftone image), a proper table is selected similarly and used to perform the density correction.