Abstract: In the case where an image is formed with a mixture of large and small droplets by bi-directional printing in an ink jet printing apparatus in which ink is ejected in the form of, e.g., a droplet for printing operation while scanning by a print head, misalignment caused by a difference in ejection speed between the large and small droplets is prevented.

Abstract: The present invention reduces a difference in speed between a main drop section and a tailing section of a ejected ink droplet by heating a front heater and a rear heater provided for one nozzle with a predetermined time lag and thus, the ink dot formed from the main drop section and the tailing section on a printing medium can be more approximate to a circle. Thereby, it is possible to prevent print quality from being degraded by the tailing section separated from the main drop section of the ink droplet ejected from an ink jet printing apparatus of serial type.

Abstract: 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.

Abstract: 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.

Abstract: A paper feed operation is performed by a width less than one pixel (½) in addition to an integer multiple number of pixels (n/2) with respect to a basic number of pixels inherent to an ink jet recording apparatus having a multi nozzle head having n nozzles. When a plurality of tines of pixel recording operations are performed for a single pixel region, ink dots land at a distance less than one pixel (½) at the pixel density. Thus, a variation in ink surface density on a recording sheet in an overlapping print operation is reduced, thereby efficiently increasing the image density, and preventing blurring by promoting absorption and evaporation of an ink to and from a paper sheet.

Abstract: An ink-jet printing apparatus and an ink-jet printing method allow the printing of an image with a high quality without causing the change in ink color coming out on the printing medium with keeping the printing conditions constantly regardless of changing the number of nozzles to be printed and the amount of transferring the printing medium, for example, by restricting the number of nozzles to be used in the printing, which belong to a nozzle row located on an upstream side in the sub-scan direction before changing the amount of transferring the printing medium; and restricting the number of nozzles to be used in the printing, which belong to the nozzle rows located on a downstream side in the sub-scan direction, after changing the amount of transferring the printing medium.

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: An ink jet printing apparatus comprising print means having a polarity of ejection outlet arrays each having a plurality of ejection outlets, arranged in a predetermined direction, for ejecting ink, scanning means for scanningly moving the print means relative to the print medium in a main scan direction which is different from the predetermined direction during a printing operation, and means for feeding the print medium relative to the print means in a direction which is different from the main scan direction, wherein an image is formed on the print medium while repeating scanning operation of the scanning means and feeding operation by the feeding means, includes information obtain means for obtaining image information corresponding to at least one of the ejection outlet arrays with respect to a predetermined area of image data to be printed; and selecting means for selecting such a portion in the at least one of ejection outlet arrays as is to effect printing for the image data in the predetermined area,

Abstract: A printing apparatus can reduce degradation in print quality of a printed image, notably in a highlight portion or an intermediate gradation portion in the case where the image is printed by forming dots of a plurality of sizes. Specifically, data causing larger and smaller cyan ink droplets, respectively, to be ejected are independently subjected to a conversion to n-value process. Thus, the data for larger ink droplets is present in a portion of printing data which corresponds to the highlight portion or intermediate gradation portion of the image. During printing, larger dots are formed in this area, thereby making it difficult to perceive possible stripes caused by the offset of the positions at which smaller dots impact a sheet.

Abstract: With a printing apparatus and a head driving method according to the present invention, a plurality of printing heads having a plurality of recording elements and a printing medium are relatively moved in a prescribed direction, and the plurality of recording elements of each printing head are divided into a plurality of blocks and each element in each block are driven in a prescribed sequence during the relative movement. As a print position offset between the plurality of printing heads in the prescribed direction on the printing medium is detected and the detected amount is greater than a prescribed amount, on the basis of block sequence designater, an in-block driving sequence is set independently for the each printing head and on the basis of a sequence generated by block sequence generater, the each printing head is driven.

Abstract: A first printing pattern is formed for a patch by means of a paper feed upstream side part of a black head. Then, a second printing pattern is formed for the patch by means of a cyan head in the following scans, and density of the patch is read by a reflection optical sensor in a scan after the completion of both patterns.

Abstract: A print method according to the present invention uses a printer apparatus based on a multipass printing method to reduce the unevenness of colors associated with a scanning direction even during bidirectional color printing. For this purpose, sets of two print heads that apply cyan (C), magenta (M), and yellow (Y) inks are arranged so as to be symmetrical in the scanning direction so that a plurality of secondary color pixels arranged in a raster direction can be formed by changing an ink application order (C→M and M→C). Consequently, the plurality of secondary color pixels arranged in the raster direction undergo the different ink application orders, so that the application order remains the same whether the pixels are formed during forward or backward scanning. Therefore, the unevenness of colors associated with the ink application order can be reduced.

Abstract: The present invention achieves formation of a 2n-value image with data of n bits, thereby reducing the amount of image information to be transferred and processed, while improving the tonal rendition, and thereby realizing a high-quality recording system for dot matrix recording suitable for personal use. For this purpose there is disclosed an ink jet recording apparatus and a method therefor, comprising an image process unit for generating multi-value information, an identification unit for identifying that the image data are multi-value information, an identification unit for the recording head, and an analysis unit for decoding the n-bit information, and featured by effecting multi-value recording while processing the n-bit data as multi-value information.

Abstract: A complete image is obtained by performing printing scan for M times (M is an integral number: M ≧1) using N printing elements (N is an integral number: N≧2) on the same printing area of in a front side of the printing medium in the direction of transporting the printing medium. On the other hand, a complete image is also obtained by performing printing scan for K times (K is an integral number: K >M) using L printing elements (L is an integral number: L≦N) on the same printing area in rear side of the printing medium in the direction of transporting the printing medium.

Abstract: Images are printed with a reduced extent of a joint streak regardless of the type of a printing medium or the number of printing passes and a printing speed is increased without executing an unwanted thinning for correcting the joint streak. More specifically, printing method information added to print data is obtained, and it is determined on the basis of this information whether or not to execute a thinning process. Consequently, inter-band data correction process based on the thinning can be executed depending on the type of the print medium and the number of printing passes, thereby achieving an appropriate thinning depending on the type of the print medium or the like. When the thinning is not to be executed, all the processes related to the thinning can be omitted to prevent a decrease in printing speed.

Abstract: 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.

Abstract: An ink jet recording apparatus wherein recording is effected while a recording head having a plurality of recording elements arranged in a first direction is scanningly moved relative to a recording material in a second direction which is different from the first direction, the apparatus including scanning means for scanningly moving relative to the recording material in the second direction; control means for controlling driving of the recording head such that while scanningly moving the recording head in the second direction, the recording is effected such that a recording band region which extends in the second region and which is recorded using a part of continuous recording elements and a non-recording band region which is not recorded, appears alternately, and by a different scanning movement, the non-recording band region is recorded.

Abstract: A construction of a printing apparatus wherein a printing registration with respect to forward and reverse scans of a printing head and a printing registration with respect to a plurality of printing heads are automatically carried out is realized without rendering the apparatus complex or causing its production cost to rise. To this end, the optical sensor for measuring patterns formed for use in printing registration is also used to serve other purposes such as a detection of a printing home position or a detection of a printing medium's end. Furthermore, by appropriately controlling a single optical sensor according to each of various intended purposes, the optimum characteristics are utilized in each respective operating mode. Because of the above, the addition of sensors to be used only for the purpose of printing registration and the accompanying rise of the print apparatus production cost are restrained.

Abstract: In a recording apparatus for effecting recording with a recording head on a recording medium,

Abstract: An ink jet recording apparatus comprises an ink jet recording head provided with a plurality of recording elements for generating energy to be utilized for discharging ink, a plurality of flow paths for retaining ink to receive the energy, a plurality of ink discharge ports for discharging ink, and a plurality of recording element substrates, and a cap member for capping the discharge ports of the ink jet recording head. For this recording apparatus, the plurality of recording element substrates, the thickness of one recording element substrate of which is different from that of the other recording element substrate, are arranged adjacent to each other on a substantially even flat plane, and the cap member is made capable of capping the discharge ports of the plurality of recording element bases plates altogether on the substantially even flat plane.