Abstract: An ink jet recording head that is capable of avoiding damages due to cavitation of an electrothermal converting element and thus extending its life is provided. The ink jet recording head comprises a plurality of ink discharge ports for discharging ink; a plurality of electrothermal converting elements provided to be associated with each of the ink discharge ports, respectively, for bubbling and discharging the ink; a plurality of pressure chambers for containing the electrothermal converting elements and providing spaces for heating and bubbling the ink; a common liquid chamber for supplying ink to the plurality of pressure chambers; and a plurality of ink flow paths for communicating the pressure chambers with the common liquid chamber. The ink flow paths are arranged such that central lines in a direction of ink supply to the pressure chambers are positioned offset from central lines of the electrothermal converting elements in the same direction.

Abstract: An ink jet head according to the present invention comprises multiple discharge ports for discharging ink, multiple ink flow paths for communicating with the discharge ports, and heat generating elements for generating bubble in ink filling the ink flow paths. Two heat generating elements are arranged in each ink flow path, and the discharge ports are arranged along a line that is extended, from the center of a pressure generation region formed by the two heat generating elements, in the normal direction relative to the surface of the substrate. The pitch for the arrangement of the heat generating elements is equal to or greater than 600 dpi, and the interval dhn between a partition wall defining the ink flow path and the heat generating element adjacent to the partition wall is equal to or smaller than 4 &mgr;m.

Abstract: This invention provides an image printing apparatus in which, when the printhead temperature rises in driving the printhead at a high speed, the ink discharge amount is optimized in accordance with the temperature rise to achieve high-quality, high-efficiency printing. For this purpose, in an image printing system using a time division simultaneous driving method of grouping a predetermined number of printing elements into a plurality of blocks every predetermined number of printing elements and driving printing elements belonging to the same block at the same driving timing, if the printhead falls within a predetermined temperature range, droplets are discharged using all blocks to print an image. To the contrary, if the printhead reaches the predetermined temperature or higher, blocks to be used are restricted in accordance with the printhead temperature, the total number of droplets is decreased, and the amount of one droplet is increased to print an image.

Abstract: In an ink jet recording head according to the present invention in which a small ink droplet and a large ink droplet can be discharged, a common liquid chamber is connected to discharge ports via ink flow paths and pressure chambers, and ink droplets are discharged from the discharge ports by utilizing thermal energy of heaters. Widths of the ink flow paths are narrower than widths of the pressure chambers so that the ink flow paths act as restriction portions. When it is assumed that a sectional area of the small liquid droplet ink flow path is SS, a sectional area of the small liquid droplet pressure chamber is SRS, a sectional area of the large liquid droplet ink flow path is SL and a sectional area of the large liquid droplet pressure chamber is SRL, a relationship SS/SRS<SL/SRL is established. According to the present invention, with this arrangement, even in the nozzle for discharging the small ink droplet, loss is reduced and energy efficiency can be enhanced.

Abstract: This invention provides an image printing apparatus in which, when the printhead temperature rises in driving the printhead at a high speed, the ink discharge amount is optimized in accordance with the temperature rise to achieve high-quality, high-efficiency printing. For this purpose, in an image printing system using a time division simultaneous driving method of grouping a predetermined printing elements into a plurality of blocks every predetermined number of printing elements and driving printing elements belonging to the same block at the same driving timing, if the printhead falls within a predetermined temperature range, droplets are discharged using all blocks to print an image. To the contrary, if the printhead reaches the predetermined temperature or higher, blocks to be used are restricted in accordance with the printhead temperature, the total number of droplets is decreased, and the amount of one droplet is increased to print an image.

Abstract: In ink jet printing by ejecting ink drops, a deviation in droplet ejection is corrected to less than one dot width. A delay value is determined from a deviation amount of dots formed by each nozzle array, and drive timing of an ejection heater is delayed in four steps in each of block units according to the delay value so as to adjust the ejection timing of an ink drop. Exact superposition of printing dots of ink and treatment liquid ejected from each nozzle array is thereby simply achieved.

Abstract: In controlling recording executed by an ink jet recording head for ejecting a recording liquid, the present invention uses a temperature sensor to detect the temperature of the recording head, prints print image data after thinning the data depending on the detected temperature, and controls drive pulses so as to provide data that has not been thinned with a sufficient amount of ejection, thereby precluding ink from being excessively ejected despite an increase in the temperature of the ink jet recording head to avoid insufficient ejection recovery (refilling) in order to prevent the corresponding image from being disturbed.

Abstract: An ink jet recording head that is capable of avoiding damages due to cavitation of an electrothermal converting element and thus extending its life is provided. The ink jet recording head comprises a plurality of ink discharge ports for discharging ink; a plurality of electrothermal converting elements provided to be associated with each of the ink discharge ports, respectively, for bubbling and discharging the ink; a plurality of pressure chambers for containing the electrothermal converting elements and providing spaces for heating and bubbling the ink; a common liquid chamber for supplying ink to the plurality of pressure chambers; and a plurality of ink flow paths for communicating the pressure chambers with the common liquid chamber. The ink flow paths are arranged such that central lines in a direction of ink supply to the pressure chambers are positioned offset from central lines of the electrothermal converting elements in the same direction.

Abstract: A recording apparatus and a recording method for controlling and driving a recording head so that an image region formed by a first ink is located between alternate image regions formed by a second ink and that the ends of a region onto which a liquid is ejected are located with substantially the same interval as the end-to-end interval of the image region of the first ink, and are shifted to a plurality of locations. A plurality of timings of ejecting the liquid corresponding to the plurality of locations are stored in a memory device. Of these timings an optimum one is selected and input according to the result of recording and then the liquid is ejected at the optimum timing during recording.

Abstract: When a plurality of heaters in the printing head are driven and the pulse width is controlled according to a change in the voltage drop corresponding to the number of driven heaters, the control range of the pulse width is properly determined to ensure a stable ink ejection. More specifically, the driving bit number for each block representing the number of heaters to be driven is counted; and based on this count value, a table is referenced to determine the pulse width of a single pulse. Then, in an inappropriate range of pulse width where the ink ejection amount varies largely, the single pulse is changed into a double pulse by referencing the table with the pulse width to obtain a double pulse driving waveform.

Abstract: An ink jet recording apparatus is to record by discharging ink and colorless record processing liquid to a recording medium from ink discharge ports and record processing liquid discharge ports. A detector detects discharge or non-discharge from every discharge port. The discharge recovery process for the processing liquid discharge ports is executed by discharging record processing liquid out of non-discharged ports to the recording medium. With the discharge recovery process thus arranged to be executable on the surface of a recording medium, not only the slowdown of printing speed is prevented, but also, the apparatus main body can be made smaller because there is no need for any provision of receptacle for receiving exhausted processing liquid.

Abstract: An ink jet recording head of high printing quality including a plurality of electro-thermal transducers arranged on a substrate corresponding to respective nozzles, wherein each protective layer placed on a resistor constituting each of the plurality of electro-thermal transducers has a thickness-reduced portion at a part thereof so as to increase the distance between the center point of the air bubble of each of the plurality of electro-thermal transducers to longer than the distance between the centers of gravity of each of the plurality of electro-thermal transducers. With the ink jet recording head, the relationship between the amount and the speed of ejected ink droplets can be optimized in accordance with the size of areas of the electro-thermal transducers.

Abstract: A printing apparatus has an ink-jet printing head having one nozzle array for ejecting an ink, and the other nozzle array for ejecting a printing improvement liquid containing a substance making a coloring agent in the ink insoluble or coagulate. When the printing improvement liquid is ejected in advance of ejection of the ink, the ejection speed of the ink is set to be lower than the ejection speed of the printing improvement liquid. When the ink is ejected in advance of ejection of the printing improvement liquid, the ejection speed of the printing improvement liquid is set to be lower than the ejection speed of the ink. The printing apparatus is capable of preventing ejection failure or deflection of the ejecting direction due to rebounding of the printing improvement liquid or mist thereof.

Abstract: An ink-jet recording apparatus of the present invention is for eliminating the difference in printed results generated from an offset between the positions to which a main drop and satellite drop of ink are discharged respectively, and generated also from the difference in the ejecting order of processing liquid with respect to ink. The apparatus is constructed such that in a scanning operation in which a satellite ink drop Da2 is dropped onto a main ink drop Da1 ejected from the ink head section in a superimposed manner, the processing liquid Sa falls after the ink dot formed on the recording paper 16 is expanded to some extent, whereas in a scanning operation in which the satellite drop Db2 is dropped at a position offset from the position of the main drop Db1, the processing liquid Sb is first ejected, and those ink drops Db1 and Db2 are discharged thereafter, so as to suppress expansion of the ink dot, making thus a dot having substantially the same size with that formed in the above scanning case.