Abstract: During a printing operation, a recording device is switched from a normal mode to a refresh ejection mode so as to temporarily increase an ejection frequency. A refresh ink droplet ejected in the refresh ejection mode is deflected to impinge on an ink collector. Recording ink droplets ejected in the refresh ejection mode are deflected and impinge on a recording sheet at positions that are shifted by gradually smaller distances.

Abstract: When a pixel-dividing number is increased to a predetermined number or more, then nozzles in each nozzle group become in one-to-one correspondence with the sub-pixel number, so that only one of the nozzles performs ink ejection at one time. Accordingly an analog driving signal drives only a single nozzle in the corresponding group at one time. Therefore, by trimming the analog driving signal in accordance with a subject nozzle each time, the all-amount trimming is possible without providing a large number of analog-driving-signal generating devices for all of the nozzles.

Abstract: An inkjet head selectively ejects recording ink droplets and refresh ink droplets. The recording ink droplets are deflected so as to impinge on target locations on a recording medium, thereby forming recording dots thereon. On the other hand, the refresh ink droplets are deflected so as to impinge on an ink absorbing member. The ink clinging on the ink absorbing member is collected into an ink tank and reused. The ink absorbing member functions as a filter for preventing impurities being collected into the ink tank along with the ink.

Abstract: When ink droplets are ejected, angled or splashed where a plurality of minute ink droplets are generated, angled or splashed ink clings on an electrode 401, 402 and increases the amount of electric current conducted therethrough. Hence, the defectiveness of ink ejection can be detected by monitoring the amount of the electric current. When the defectiveness of ink ejection is detected, ejection data D is retrieved and updates the ejection data D based on a condition register S, and set to a defect register E. When the defect register E has only one element that takes a condition value of 1 indicating defectiveness, the corresponding nozzle is identified as defective. The restoring means reallocates dots, which have been originally allocated to the defective nozzle, to neighboring nozzle.

Abstract: A charge/deflecting electrode is provided on an orifice surface of an inkjet head near nozzle orifices formed in the orifice surface. A suction tube is pressed against the orifice surface and the electrode to retain a space therebetween. When a negative pressure is generated in a suction hole of the suction tube, ink and foreign matter are sucked from the nozzle orifices. The space is asymmetric on left and right sides so the negative pressure develops a whirlpool-shaped flow including a mixture of air and ink near the suction hole.

Abstract: When positively charged ink droplets 608 from a defective nozzle impact a negatively charged deflector electrode 320, the positive charge on condenser 609 flows to the ground via a FET 618 of a photo-coupler 610. As a result, the electric discharge occurs by an amount equivalent to the charging amount of the ink droplets 608 clinging on the electrode 320. Because a switching signal 606 is “1”, the ON resistance of the photo-coupler 610 is large, and the ON resistance of the FET 620 of the photo-coupler 612 is small. Accordingly, the discharge due to the charged ink droplets 608 is detected as a large detection voltage and amplified by an operational amplifier 613 . Because the charger voltage of the condenser 609 is static and has no noise, even when the detection output 615 is highly amplified, noise during the detection is suppressed.

Abstract: A sheet-position synchronizing signal is generated once each time a recording sheet is transported by a single-line worth of distance in a sheet feed direction. A print-driving signal and a refresh-driving signal are generated within a time interval of two successive sheet-position synchronizing signal. When the print-driving signal is applied to a piezoelectric element of a nozzle, then a print ink droplet is ejected, thereby a dot is formed on a recording sheet. On the other hand, when the refresh-driving signal is applied to the piezoelectric element, then a negatively-charged refreshing ink droplet is ejected. The refresh ink droplet refreshing ink droplet is deflected by an electric field and collected by a metal mesh without reaching the recording sheet.

Abstract: An inkjet recording device includes an ink reservoir that stores ink, a recording head having a plurality of nozzle holes for forming recording dots on a recording medium by ejecting ink particles from the plurality of nozzle holes onto the recording medium positioned opposite the plurality of nozzle holes, an ink channel for supplying ink from the ink reservoir to the recording head, ink discharging means for discharging ink from the recording head and the ink channel, evacuating means for creating a vacuum state in the recording head and the ink channel, and ink filling means for filling the evacuated recording head and ink channel with deaerated ink. The ink discharging means divides the recording head and the ink channel into a plurality of sections and independently discharges ink from each section of the recording head and the ink channel.

Abstract: An inkjet head selectively ejects recording ink droplets and refresh ink droplets. The recording ink droplets are deflected so as to impinge on target locations on a recording medium, thereby forming recording dots thereon. On the other hand, the refresh ink droplets are deflected so as to impinge on an ink absorbing member. The ink clinging on the ink absorbing member is collected into an ink tank and reused. The ink absorbing member functions as a filter for preventing impurities being collected into the ink tank along with the ink.

Abstract: An orifice electrode/ink receiving member 11 is attached to an orifice plate 13 that is attached to a recording head module 10. An ink absorbing member 111 is embedded in a lower surface of the orifice electrode/ink receiving member 11. A recording ink droplet 14 ejected through an orifice 12 is deflected as needed by an angled electric field 85 and then impinges on a recording sheet 60 to form a recording dot 70. On the other hand, a refresh ink droplet 15 is deflected by the angled electric field 85 and impinges on the ink absorbing member 111 of the orifice electrode/ink receiving member 11 after flying in a U-turn path. In this configuration, the ink absorbing member 111 provided to the orifice electrode/ink receiving member 11 collects ink, so that there is no need to increase a gap between the recording head module 10 and the recording sheet 60 so much in order to dispose the ink absorbing member 111, preventing decrease in recording precision and paper jam.

Abstract: As shown in FIG. 7(e), an electric field is generated at timing T3 at which an ink droplet 14 is divided, end moves the negative ions toward a main ink portion 14m. As shown in FIG. 7(e′), a resultant main ink droplet 14M has an increased charging amount of −3 q, and a satellite ink droplet 14S has a decreased charging amount of −6 q. When the main ink droplet 14M and the satellite ink droplet 14S have the mass of 1 m and Qs, respectively, then the relative charging amounts of the main ink droplet 14M and the satellite ink droplet 14S are both −3. Hence, the deflection amount of the satellite ink droplet 14S is approximately equal to the deflection amount of the main ink droplet 14M. Accordingly, the satellite ink droplet 14S and the rain ink droplet 14M impact the recording sheet 60 on the same spot or on the extremely close spots, thereby forming a single dot.

Abstract: An electrode plate includes a base electrode plate, an edge forming electrode plate on the base electrode plate, and an ink reception absorption bodies embedded into the edge forming electrode plate. A plurality of head modules are precisely attached to the electrode plate so that nozzle rows formed in nozzle plates of the head modules extend following corresponding windows formed in the electrode plate. Such a precise attachment is realized by matching the pinholes formed in the nozzle plates to the corresponding pinholes formed in the base electrode plate and the edge-forming electrode plate.

Abstract: When a pixel-dividing number is increased to a predetermined number or more, then nozzles in each nozzle group become in one-to-one correspondence with the sub-pixel number, so that only one of the nozzles performs ink ejection at one time. Accordingly an analog driving signal drives only a single nozzle in the corresponding group at one time. Therefore, by trimming the analog driving signal in accordance with a subject nozzle each time, the all-amount trimming is possible without providing a large number of analog-driving-signal generating devices for all of the nozzles.

Abstract: A plurality of nozzle rows are formed in a nozzle plate, and nozzle electrodes for generating a deflecting field are provided for every two nozzle rows. Each electrode is attached to the nozzle plate so as to locate between the corresponding adjacent two nozzles. Ink reception absorption bodies are embedded in the bottom surface of the electrodes. Refresh ink droplets deflected by the deflecting field travels along U-turn paths and impinge on the ink reception absorption bodies.

Abstract: A back electrode 30 is provided at a rear surface side of a recording sheet 60. An orifice electrode 11 is attached to an orifice plate 15 of a head module 10. The orifice electrode 11, the orifice plate 15, and ink filling in a nozzle element 2 are electrically connected to the ground. The back electrode 30 has the potential corresponding to that of a charging/deflecting signal. With this configuration, the orifice electrode 11, a pressure chamber 13, and the back electrode 30 together generates an inclined electric field 85 at a position a close to a center trajectory 90. A charged ink droplet is deflected greatly by the inclined electric field 85, at an early stage of the ink flight, and even greater deflection can be achieved as the flight proceeds.

Abstract: An electrode plate includes a base electrode plate, an edge forming electrode plate on the base electrode plate, and an ink reception absorption bodies embedded into the edge forming electrode plate. A plurality of head modules are precisely attached to the electrode plate so that nozzle rows formed in nozzle plates of the head modules extend following corresponding windows formed in the electrode plate. Such a precise attachment is realized by matching the pinholes formed in the nozzle plates to the corresponding pinholes formed in the base electrode plate and the edge-forming electrode plate.

Abstract: An ink jet recording device 1 includes a plurality of head modules 101 each formed with a plurality of nozzles. The ink jet recording device 1 prints a test pattern using the all nozzle of the head modules 101. Precise positions of dots forming the test pattern are detected, based on which positional shifts of the head modules 101 are calculated. The deflection amount and ink ejection timing for each head module 101 are changed based on the detected positional shift. In this manner, positional shifts of the assembled head modules 101 are electrically corrected without mechanically changing the physical positions of the head modules 101.

Abstract: A sheet-position synchronizing signal is generated once each time a recording sheet is transported by a single-line worth of distance in a sheet feed direction. A print-driving signal and a refresh-driving signal are generated within a time interval of two successive sheet-position synchronizing signal. When the print-driving signal is applied to a piezoelectric element of a nozzle, then a print ink droplet is ejected, thereby a dot is formed on a recording sheet. On the other hand, when the refresh-driving signal is applied to the piezoelectric element, then a negatively-charged refreshing ink droplet is ejected. The refresh ink droplet refreshing ink droplet is deflected by an electric field and collected by a metal mesh without reaching the recording sheet.

Abstract: A recording head 200 has a plurality of nozzle orifices aligned in a row extending in a first direction. The recording head 200 is arranged with the nozzle orifices in confrontation with a recording medium P. The recording medium P is moved in a second direction B with respect to the recording head 200. Also, ink droplets ejected from the nozzle orifices are charged to a charged amount that corresponds to deflection amount of the ink droplets. The charged ink droplets are deflected in a direction perpendicular to a main scanning line. The plurality of ink droplets ejected from the plurality of nozzle orifices impinge on the same pixel position or at a nearby position so that it is possible to impinge multiple droplets at the same pixel position or a nearby position. As a result, it is possible to back up broken nozzles and to reduce recording distortion.

Abstract: As shown in FIG. 7(e), an electric field is generated at timing T3 at which an ink droplet 14 is divided, end moves the negative ions toward a main ink portion 14m As shown in FIG. 7(e′), a resultant main ink droplet 14M has an increased charging amount of −3 q, and a satellite ink droplet 14S has a decreased charging amount of −6 q.