Abstract: The invention describes a number of methods and apparatus for shortening the inter-message gap on a continuous inkjet printer. Included is a novel phase testing methodology.

Abstract: An inkjet recording apparatus, which can enhance the reliability of the phase search result to detect the optimal timing when the ink particles are electrically charged by the electrification electrode and secure the stable printing quality, is provided.

Abstract: A print head of a continuous ink jet printer, including, in a cover: means for producing at least one ink jet; means for separating drops of jets intended for printing from those that do not serve for printing; a slot, enabling drops intended for printing to get out; a recovery gutter (7) for drops not intended for printing, the recovery gutter comprising an ink recovery volume (12); at least one detection conductor (20), arranged inside the head; means (16) for detecting a variation in impedance of at least one of the detection conductors when ink (21) is present in contact with the conductor or with a dielectric layer (22) in contact therewith.

Abstract: In order to obtain homogeneous ink for CIJ printers, an inkjet is divided into individual equally large ink droplets, at least part of the ink droplets is provided with an electric charge, and the ink droplets are guided by a deflection device. The ink droplets which are deflected by a predefined amount are collected by a homogenization droplet catcher and are used for printing.

Abstract: A voltage is applied between first and second deflecting electrodes from a deflecting voltage controller, whereby an electric field is formed between the first and second deflecting electrodes in a direction perpendicular to electrode surfaces. An electric line of force is generated from a direction perpendicular to the electrode surface of the first deflecting electrode and made perpendicularly incident on the electrode surface of the second deflecting electrode. Since the first and second deflecting electrodes are parallel to each other, a plurality of parallel electric lines of force are formed perpendicularly to the electrode surfaces of the first and second deflecting electrodes. Droplets after passing charged electrodes fly in a region where this deflecting electric field is formed, whereby charged droplets are deflected in a direction in which the charged droplets approach the second electrode having opposite charging polarity. The charged droplets form a printing pattern.

Abstract: A method for forming an image includes providing a media support adapted to receive media; providing a recording head comprising a plurality of recording channels, wherein each recording channel is adapted to form an image pixel column while scanning over the media; providing an image data file comprising one or more arrangements of image data columns; assigning first image data from a single image data column to a first recording channel of the recording head; operating the first recording channel to form a first image pixel column solely in accordance with the assigned first image data; assigning second image data from each image data column of a plurality of the image data columns to a second recording channel of the recording head; operating the second recording channel to form a second image pixel column in accordance with the assigned second image data; and operating the recording head to form the image.

Abstract: According to the present invention, there is disclosed an image forming apparatus comprising a constitution driven/controlled independently for each recording head. The apparatus rewrites image data or parameters or changes a driving voltage at a desired timing, and realizes a uniform or appropriate density of an image formed by control of an ink spout amount based on a temperature detection signal of the recording head detected by a temperature detection unit disposed in each recording head. The apparatus is capable of remarkably narrowing a mutual conveying interval among a plurality of conveyed recording mediums.

Abstract: Disclosed is a system for printing an image comprising a plurality of pixels, the system comprising: a carriage arranged to make a plurality of passes along a scanning axis with respect to a print medium; a plurality of printheads mounted on the carriage, each printhead corresponding to a different ink color and comprising at least one ejection nozzle; and, a print controller configured to receive data defining for each pass zero or more locations at which to deposit each of the ink colors to produce each pixel; wherein the data is such that for at least one pixel, at least one of the ink colors is deposited at substantially more locations on one pass relative to the other passes.

Abstract: The present invention provides methods for forming an image with orthogonality corrected image data. A recording head includes a plurality of recording channels which form an image on media. Each recording channel forms an image pixel column. An image data file includes a plurality of image data columns. Different portions of each of a first image data column and a second image data column are assigned to different recording channels. First image data from a portion of the first image data column is substituted with zero image data and is assigned along with image data from another portion of the second image data column to a first recording channel which forms a first image pixel column. The first image data can also be assigned to a second recording channel which forms a second image pixel column. The second image data column is formed while scanning along a direction different than the scanning direction employed to form the first image pixel column.

Abstract: A method for forming an image in a skewed recording apparatus comprising a recording head comprising a plurality of recording channels, the method includes providing an image data file comprising a plurality of image data columns; assigning different portions of each image data column to different recording channels; substituting first image data from a first image data column assigned to a first recording channel with second image data from a second image data column assigned to a second recording channel; and operating the recording head to form the image.

Abstract: A method relating to ascertaining and adjusting friction between media pages in a document feeder. The method includes: detecting slipping of a media page when traversing from a stack of media pages to passing through a path defined by the document feeder; and sending a signal to a fluid-containing cartridge to spray small drops of fluid onto the slipping media page soon after the slipping is detected while the media page passes through the document feeder. A system and apparatus are also associated with the above method.

Abstract: A method for operating a continuous inkjet printer, the method includes forming drops with a drop formation period being the time between consecutive drop formations; creating a portion of the drops that strike the print media for forming print drops; creating a portion of the created drops that do not strike the print media for forming catch drops; creating the print drops to print on a series of consecutive pixel locations; wherein a time between the creation of consecutive print drops is inconsistent which causes an additional catch drop so that a gap is created; wherein when a gap is created, adjusting a velocity of the print drop adjacent to the gap to cause the print drop to shift slightly toward the gap.

Abstract: A signal generating device to be installed in a liquid ejecting apparatus which comprises a liquid ejector operable to eject liquid and a carriage operable to carry the liquid ejector, the signal generating device comprising: a first generator to generate first pulse signals at first intervals corresponding to a velocity of the carriage; an estimator to estimate an interval of the first pulse signals which will be generated by the first generator based on a variation of an acceleration of the carriage as a second interval; a second generator to generate second pulse signals at third intervals which are obtained by dividing the second interval; and a third timing signal generator to generate a timing signal determining a timing at which the liquid is ejected from the liquid ejector, based on the second pulse signals.

Abstract: A liquid ejection head, having: an insulating nozzle plate provided with a nozzle having, a liquid supply port to supply liquid and an ejection port to eject the liquid supplied from the liquid supply port onto a substrate; a cavity communicating with the liquid supply port to reserve the liquid to be ejected from the ejection port; an electrostatic voltage applying device to generate an electrostatic attraction force by applying an electrostatic voltage between the liquid in the nozzle and the cavity, and the substrate; and a control device to control the electrostatic voltage applying device for conducting polarization relaxation operation by applying an electrostatic voltage having reverse polarity opposite to that of the electrostatic voltage applied in liquid ejection, wherein the nozzle is a flat nozzle and the control device.

Abstract: A method and apparatus for forming fluid droplets includes a nozzle channel, a pressurized source of a non-conductive fluid in fluid communication with the nozzle channel, and a stimulation electrode. The pressurized source is operable to form a jet of the non-conductive fluid through the nozzle channel. At least one portion of the stimulation electrode is electrically conductive and contactable with a portion of the non-conductive fluid jet. The at least one electrically conductive and contactable portion of the stimulation electrode is operable to transfer an electrical charge to a region of the portion of the non-conductive fluid jet with the electrical charge stimulating the non-conductive fluid jet to form a non-conductive fluid droplet.

Abstract: An image processing apparatus executes an error diffusion process to multivalue image data consisting of a plurality of density components. A first processor executes the error diffusion process by changing at least one of a quantization threshold value and a quantization diffusion coefficient which are used for the error diffusion process based on a value of the multivalue image data of the density components or a value calculated from the multivalue image data value. A second processor executes the error diffusion process by setting the quantization threshold value and the quantization diffusion coefficient which are used for the error diffusion process into fixed values. An error diffusion processing controller controls to execute the error diffusion process to at least one color among the density components by the first processor and execute the error diffusion process to other density components by the second processor.

Abstract: In an ink-jet printing a succession of ink droplets are projected along a longitudinal trajectory at a target substrate. A group of droplets is selected from the succession in the trajectory, and this the group of droplets is combined by electrostatically accelerating upstream droplets of the group and/or decelerating downstream droplets of the group into a single drop.

Abstract: In an image forming apparatus, a liquid ejection head has at least one ejection hole, and a conveyor moves a recording medium relative to the ejection head. A deflector deflects liquid droplets ejected from the ejection hole in a direction including at least a component of a direction substantially parallel to relative conveyance direction of the recording medium. A deflection angle setter sets two or more deflection angles such that when dots mutually adjacent in the direction substantially parallel to the relative conveyance direction of the medium are formed in an overlapping fashion, directions of flight of droplets ejected consecutively are deflected such that their directions of flight become different from each other. Droplet landing time differential between the first droplet and the second droplet becomes equal to or greater than quasi-fixing time period from a landing time of the first liquid droplet until the first liquid droplet becomes quasi-fixed.

Abstract: A method of printing includes associating a pixel area of a recording medium with a nozzle and a time interval during which a fluid drop ejected from the nozzle can impinge the pixel area of the recording medium. The time interval is divided into a plurality of subintervals. Some of the plurality of subintervals are grouped into blocks. One of two labels is associated with each block. The first label defines a printing drop and the second label defines non-printing drops. No drop forming pulse is associated between subintervals of each block having the first label. A drop forming pulse is associated between each subinterval of each block having the second label. A drop forming pulse is associated between other subintervals between each pair of consecutive blocks. Drops are caused to be ejected from the nozzle based on the associated drop forming pulses.

Abstract: A system and method for image correction in a direct marking system is provided using input scaling. The system and method utilize spatial dependent scale factors for each color of a liquid ink printer in the direct marking system. The value of each scale factor depends upon the ratio of the target mass to the average mass of the ink drops in the region to be corrected. The target mass is typically equal to or near the lowest average mass to insure that all regions can be adjusted to common output color. All input values received by the direct marking system and corresponding to a region to be corrected are multiplied by the appropriate scale factor to correct for drop volume variations among different printheads of the direct marking system. Each printhead includes a plurality of ejectors for depositing ink on a recording medium.

Abstract: A method and apparatus for forming fluid droplets includes a nozzle channel, a pressurized source of a non-conductive fluid in fluid communication with the nozzle channel, and a stimulation electrode. The pressurized source is operable to form a jet of the non-conductive fluid through the nozzle channel. At least one portion of the stimulation electrode is electrically conductive and contactable with a portion of the non-conductive fluid jet. The at least one electrically conductive and contactable portion of the stimulation electrode is operable to transfer an electrical charge to a region of the portion of the non-conductive fluid jet with the electrical charge stimulating the non-conductive fluid jet to form a non-conductive fluid droplet.

Abstract: An ink jet printing system includes a printhead generating a plurality of continuous ink jets that are in a row and directed toward a print receiving medium. The printhead contains a drop generator and an orifice plate that includes a plurality of nozzles to form the continuous ink jets. The orifice plate includes a stimulating device to produce first and second synchronous drop breakoffs in a phased relationship and each ink jet in the drop breakoffs alternate producing plurality of drops in a phased relationship. A charge plate is placed opposite the drop generator and includes a plurality of drop charging electrodes adjacent the continuous ink jets. A controller is in communication with each drop charging electrode and supplies a plurality of synchronized controlled drop selection pulses to the drop charging electrodes.

Abstract: A sensor configuration for use in detecting ink droplets ejected from an ink drop generator is provided. The sensor configuration includes a sensing element configured to receive a biasing voltage which creates an electric field from the sensing element to the ink drop generator. The sensor configuration also includes a sensing amplifier coupled to the sensing element, whereby the sensing element in imparted with an electrical stimulus when at least one ink droplet is ejected in the presence of the electric field, and thereafter passes in close proximity to the sensing element without substantially contacting the sensing element. Sensor configurations with a separate electrically biasing element which may or may not contact the ink droplets are also provided. Additionally, a printing mechanism having such sensor configurations and a method of making ink drop detection measurements are also provided.

Abstract: A printhead assembly includes at least one printhead module including a printhead chip. A carrier supports the, or each, printhead module in an operative position for printing on print media. Mating formations are carried by the, or each, printhead module and the carrier such that, when the, or each, printhead module is mounted on the carrier, electrical contact is made between electrical contacts of the, or each, printhead module and electrical contacts of the carrier.

Abstract: Ink particles that start flying toward the printing medium P earlier than or later than the ink particles for the line central area are used as ink particles for the line ends. Accordingly, it is possible to compensate for the affects of electrical charges onto the flying path of the ink particles for the line end portions, reducing the amount of bending at the ends of the printed line such that the bend is not noticeable, thereby improving the quality of printing to satisfy consumer demands.

Abstract: A method is disclosed for controlling a multi-nozzle CIJ printhead having a pressure modulator for causing streams of ink emitted from the nozzles to be broken up into individual droplets, and charge electrodes 6 and charge electrode controllers for controllably applying a charge to individual ones of the droplets in each stream. The method involves generating a modulation waveform to operate the pressure modulator to cause droplets to be generated in each stream and operating the charge controllers to supply a charge signal waveform to each charge electrode. The charges applied to the streams of droplets are compared to a reference or threshold value. The number of droplet streams in which the droplet charges exceed the reference or threshold value is determined plural times and an average value for the number is calculated. This step is repeated a number of times and if the average is less than the average previously calculated then the threshold or reference value is reduced.

Abstract: A method for adjusting the amplitude of the pressure modulation waveform in a multi-nozzle continuous jet printhead having a pressure modulator for causing streams of ink emitted from the nozzles to be broken up into individual droplets, and charge electrodes and change electrode controllers for controllably applying a charge to individual ones of the droplets in each stream.

Abstract: Process for compensation of mechanical defects in an ink jet printer in which the ink viscosity, the jet velocity, the distance at which the ink jet is broken into droplets and the phase are independently servocontrolled to respect set values, process according to which the droplet arrival position is compared with a reference position, and mechanical defects are compensated by varying the electrical charge on the droplets. The invention also relates to a printer equipped with checking and servocontrol means so that compensation according to the process can be applied. The mechanical assembly of the printer will thus be simplified.

Abstract: A method and apparatus for accurately determining and setting the optimal nozzle drive voltage for an ink jet printer. The current carried by charged test drops is monitored by a sensing electrode and ammeter while the nozzle drive voltage is slowly varied between minimum and maximum points. A plot of drop current versus nozzle drive voltage provides an accurate determination of the good printing window for the particular nozzle under the operating conditions presented. This arrangement can be used for calibrating a new nozzle in an existing printer or for calibrating a new ink or font to ensure that operation will occur within the desired print window.

Abstract: An ink jet recording apparatus wherein ink drops can be controlled individually to assure high quality printing and adjustment in registration of ink nozzles in a drum circumferential direction can be performed at a sufficiently high resolution. The ink jet recording apparatus has a plurality of nozzles arranged such that drops of ink may impinge in an overlapping relationship at a location on a record medium supported on a rotary drum, and adjustment in registration of the nozzles in a drum circumferential direction is performed by a registration adjusting system by which such adjustment is performed using a registration adjusting clock signal having a frequency higher than a picture element recording signal. An optimum phase between disintegration of an ink jet and a recording pulse signal is determined in accordance with current values detected by a current detector connected to an electrically isolated conductive drop catcher.

Abstract: A segmented charge tunnel for ink jet printing having a plurality of individual segments is utilized to sequentially apply charges to a droplet stream. Precise location of the stream break-off point within the tunnel is accomplished by identifying which one of the segments of the charge tunnel is associated with the detection of a maximum charge by a downstream sensor. Precise determinations of the distance between the break-off point and the detection downstream permits accurate droplet flight time measurement to allow ink composition and spacing to be controlled.

Abstract: A method is provided for adjusting the operating amplitude of a modulation signal which influences the separation of drops from an ink jet of an ink jet printer. The method includes (1) determining the phase relationship between the modulation signal and the instants when successive drops separate from the ink jet for a plurality of amplitudes of said modulation signal (2) identifying the amplitude of the modulation signal at a predetermined characteristic point in the function of the phase relationship with the amplitude from the magnitude of the change of the phase relationship with the change of the amplitude; and (3) selecting the operating amplitude for the modulation signal in accordance with the amplitude identified in step (2).

Abstract: A pilot nozzle is provided for a multi-jet printing head. The pilot nozzle is continuously monitored to detect changes in phase due to changes in ink temperature, viscosity, pressure or other reason. Should a change occur requiring that the pilot nozzle be operated on a different clock phase, this change is made to all of the nozzles, without interrupting printing. The pilot nozzle is not used for printing, but is continuously monitored for the sole purpose of detecting phase changes.

Abstract: A microprocessor-based control system for use in ink jet printers periodically measures flow rate of marking fluid, flow time or flight time of marking fluid drops and adjusts the voltage supplied to deflection electrodes-to maintain constant character height notwithstanding changes in the printer operating environment that would otherwise result in undesirable variation in character height. An alternate embodiment uses the flow time, flow rate or flight time information to adjust the charge amplifier gain, rather than the deflection voltage, to achieve the same result.