Abstract: In an apparatus for measuring an ejection velocity of a liquid droplet ejected from a nozzle orifice of a head device which is provided with a pressure chamber communicated with the nozzle orifice and an actuator which varies pressure of liquid contained in the pressure chamber, a driver generates a drive signal to drive the actuator to eject a liquid droplet from the nozzle orifice. A photo emitter emits a light beam so as to intersect a space through which the liquid droplet passes. A photo receiver receives the light beam which has been passed through the space. A calculator calculates an ejection velocity of the liquid droplet based on a timing at which the actuator is driven and a change in a photo-receiving state of the photo receiver.

Abstract: In an apparatus for measuring a natural period of liquid in a pressure chamber formed in a head device which is provided with a nozzle orifice communicated with the pressure chamber and an actuator which varies pressure of the liquid contained in the pressure chamber, a driver generates a plurality of drive signals, each of which drives the actuator to eject a liquid droplet from the nozzle orifice under a condition different from the conditions established by the other drive signals. A light emitter emits a light beam so as to intersect a space through which the liquid droplet passes. A light receiver receives the light beam which has been passed through the space. A first calculator calculates an ejection velocity of the liquid droplet based on a timing at which the actuator is driven and a change in a photo-receiving state of the light receiver, with regard to every drive signal.

Abstract: When an refresh ink droplet ejected from a nozzle and deflected by an inclined electric field impinges on a orifice electrode/ink receiving member, electric charge is discharged from the refresh ink droplet, thereby an electric current is generated. A current-voltage converter/amplifier detects the electric current and outputs a detection signal. A defective-condition determining circuit determines an ejection condition of a nozzle element based on voltage value of the detection signal.

Abstract: A printer according to the present techniques includes a print head having at least one nozzle for ejecting an ink drop and a sensing element for detecting the ink drop. The print head includes a charge shield for imparting an electrical charge into the ink drop during ejection from the nozzle and for shielding electrical noise generated in the print head.

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: Methods and systems for detecting ink droplets ejected by a printer, and for determining if the trajectory of an ink droplet deviates from a desired trajectory. In one embodiment, the ink droplet trajectory detector has multiple electrically conductive, electrically isolated sensors. Each of said sensors is configured to generate an electrical signal when an ink droplet passes in proximity thereof, without requiring the ink droplet to physically engage any portion of said sensors. The ink droplet trajectory detector also has at least one structure orienting said sensors relative to one another.

Abstract: In one embodiment, a sensor includes two plates that form a capacitor. A droplet passing between the plates changes the capacitance of the sensor, thereby triggering an amplifier coupled to the sensor to generate an output signal. The output signal is indicative of droplet characteristics and may be used to calibrate a mechanism that dispensed the droplet.

Abstract: A bulldozer-type cleaning system is provided for removing ink residue from an electrostatic drop detecting sensor which detects ink droplets contacting the detector. A scraper head scrapes the ink residue from the sensor, and then contacts a flexible, compliant cleaning member, illustrated as a coil spring. The spring is secured at each end and is stretched when pushed by the scraper head. This stretching flexation allows the spring to trap the ink residue between the coils. As the scraper head retracts, the resulting contracting flexation of the spring squeezes the ink residue from between the coils. Any ink residue remaining on the coils dries and then flakes off the coils when the spring is stretched again during the next cleaning stroke of the scraper head. An inkjet printing mechanism having such a cleaning system, and a method of cleaning a sensor are also provided.

Abstract: A microscopic droplet detecting device for detecting a passage of droplets jetted from a nozzle of an ink jetting device, including a droplet detecting section including a paired light emitting and receiving elements, a jet control section to control the ink jetting device to jet droplets serially along the traveling course, and a jetting condition detecting section to detect a jetting condition of the nozzle based on the output signal.

Abstract: A printer device having a plurality of print heads for printing onto a print medium. Each of the print heads having a plurality of nozzles formed into at least two rows. A service station housed within the printer device having a plurality of service station units for performing servicing operations on the print heads. A plurality of ink drop detector modules being integrated into respective ones of the service station units for detecting malfunctioning nozzles on the plurality of print heads. The ink drop detector modules may be configured to test the nozzles of each row of nozzles on at least one of the print heads simultaneously. And, according to a preferred embodiment, each row of nozzles of each print head are tested simultaneously to thereby substantially reduce the amount of time required to test the functionality of the nozzles.

Abstract: The object is to provide a technique whereby a non-operating nozzle can be detected with higher accuracy. The present invention resides in a printer for printing images by ejecting ink droplets from a plurality of nozzles, wherein an optical path in which light from a light-emitting element 40a for emitting light is focused by a first focusing element 41, allowed to pass through a focusing aperture 43a that is substantially circular and smaller than the area illuminate by the light, and transmitted through the focusing aperture 43a to a light-receiving element 40b for receiving light is laid out according to a configuration in which an intersection is formed with the path described by the ink droplets ejected by the nozzles. The light-emitting element 40a is energized and caused to emit light.

Abstract: A method and apparatus for printing rasterized images while economizing printing resources, on the basis of input image data corresponding to a predetermined original format, are provided. The method includes reducing the input image relative to the original format; on the basis of the reduced-scale image, forming a raster of image points each defining either a point to be printed or a blank point of the rasterized image; enlarging the raster of points to return to the original format by inserting blank image points in the reduced raster by a predetermined filling procedure; and printing the image on the basis of the point raster enlarged to the original format.

Abstract: The present invention is directed to a system and method for a waste ink removal apparatus for cleaning ink residue from an ink drop detection sensor in a printing mechanism, comprising an assembly pivotally supported by a pivot, the assembly pivoting between a first orientation and a second orientation; an ink drop sensor located on the assembly; a pivoting device connected to the assembly and an absorbent pad located to contact the ink drop sensor when the assembly is in the second orientation, wherein operation of the pivoting device causes the assembly to pivot between the first and second orientations such that waste ink is removed from the ink drop sensor when the assembly is in the second orientation.

Abstract: An apparatus for detecting ink droplets ejected from ink drop generators has a target holder and a conductive absorbent target supported by the target holder. The apparatus for detecting ink droplets also has standoffs extending from the target holder. The apparatus for detecting ink droplets further has an actuator for moving the target holder towards the ink drop generators such that the standoffs space the target from the ink drop generators.

Abstract: Color printheads in a color inkjet printer are in a fixed order in the scanning carriage, which causes the colors to be printed in a different order when the carriage is scanned in an opposite direction. The different print order may result in a perceptible change in hue between passes in bi-directional printing. Depleted shingle masks are substituted for the nominal ones, based on print direction, at the shingle masking stage, to compensate for print-direction-induced hue shift. A look-up table indexed by a composite color tone value providing a depletion probability and a halftoning error diffusion value are used in determining when depleted shingle masks are to be invoked.

Abstract: A cleaning system is provided for cleaning ink residue from a sensor in a printing mechanism which deposits ink on the sensor, which comprises a scraper member having a head which, through relative motion of the head and sensor, gathers ink residue from the sensor; a flexible member having plural cleaning segments which, through relative motion and engagement of the flexible member and the head, flexes and collects ink residue from the head with the cleaning segments; wherein the flexible member comprises first and second springs, the first spring comprises a coil spring defining an interior space; and the second spring comprises a coil spring located in the interior space of the first spring.

Abstract: Methods and systems for detecting ink droplets ejected by a printer, and for determining if the trajectory of an ink droplet deviates from a desired trajectory. In one embodiment, the ink droplet trajectory detector has multiple electrically conductive, electrically isolated sensors. Each of said sensors is configured to generate an electrical signal when an ink droplet passes in proximity thereof, without requiring the ink droplet to physically engage any portion of said sensors. The ink droplet trajectory detector also has at least one structure orienting said sensors relative to one another.

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: An apparatus for determining the time at which a charged droplet is at a predetermined physical position comprising: first and second electrodes (1, 3) past which said droplet passes in use of said apparatus, said droplet inducing a charge on each said electrode (1, 3) as it passes; and circuitry (5, 7, 9) responsive to the charges induced on the first and second electrodes (1, 3) for determining the time at which said droplet is at said predetermined physical position midway between said electrodes (1, 3).

Abstract: E1 A CIJ printhead includes a droplet deflector electrode having one or more windows formed therein, and a phase or velocity detector electrode disposed within the window. A method of forming the electrodes by plating multiple conductive and dielectric layers is also disclosed.

Abstract: An imaging apparatus capable of inhibiting inadvertent ejection of a satellite ink droplet and method of assembling same. The imaging apparatus comprises a print head transducer including a pair of sidewalls defining a chamber therebetween, the channel having the ink body disposed therein. The transducer is in fluid communication with the ink body for inducing a first pressure wave in the ink body in order to eject an ink droplet. A waveform generator is connected to the transducer for supplying voltage waveforms to the transducer, so that the transducer induces pressure waves in the ink body. However, the first pressure wave has a reflected portion formed by the first pressure wave reflecting from the sidewalls. The reflected portion is sufficient to otherwise inadvertently eject unintended satellite ink droplets. Thus, a sensor is in fluid communication with the ink body for sensing the reflected portion and is connected to the transducer for inducing a second pressure wave in the ink body.

Abstract: Continuous jetting of liquid metal droplets for deposit on a substrate includes an ejector, a deflection device, a print chute, and a collection reservoir. Liquid metal from a cartridge in the ejector provides a continuous molten material stream through an orifice-defining structure while a vibration device creates a standing wave in the stream to break the molten material stream into individual droplets which receive charge from a charging device. The deflection device enables the positioning of the charged droplets to be controlled for placement on a substrate. Control systems assist in the calibration and control of the continuous stream to ensure that selected droplets are placed at desired locations on the substrate.

Abstract: Apparatus and techniques are disclosed for aligning the operation of the ink jet printhead cartridges of a multiple printhead ink jet swath printer that includes a print carriage that is movable along a horizontal carriage scan axis, (b) first and second ink jet printhead cartridges supported by the movable carriage for printing onto a print media that is selectively movable along a vertical media scan axis, and (c) an optical sensor supported by the movable carriage. The optical sensor includes a quad photodiode detector whose outputs are indicative of the horizontal positions of vertical test lines imaged on the detector in conjunction with horizontal alignment correction, as well as the vertical positions of horizontal test lines imaged on the detector in conjunction with vertical alignment correction.

Abstract: A printer device for emitting a medium or mixing and emitting a medium for quantitation and a medium for emission, in which a correct recording image can be formed with a suppressed running cost. At least one tank 51 is provided which has at least one first liquid chamber 52 in which is disposed a liquid holder 53. A print head is provided which has a nozzle in association with this first liquid chamber 52. Preferably, at least one second tank is provided which has a second liquid chamber in association with the first liquid chamber 52 of the first tank 51 for direct communication between the two chambers. The printer device can be configured for emitting only the emission medium of mixing the quantitation medium and the emission medium and emitting the resulting mixed liquid.

Abstract: The present disclosure relates to an ink container for providing ink to an ink jet printing system. The ink container includes an outer shell, the outer shell defining an elongate opening therein. Also included is a chassis having a fluid outlet and air inlet defined therein. The fluid outlet is in communication with an ink reservoir that is fluidically coupled to the chassis. The chassis has a shape that is complementary with the elongate opening of the outer shell. With the chassis inserted into the outer shell pressurized air provided at the air inlet pressurizes the outer shell that in turn pressurizes the ink reservoir to provide a source of pressurized ink at the fluid outlet.

Abstract: An ink drop detector that minimizes costs of a printer by employing preexisting digital signal processing elements in a printer and low cost analog sensing elements. The analog sensing elements are tuned to ink drop bursts, which include a plurality of ink drops, and the preexisting digital signal processing elements extract ink drop characterization information from sensed analog signals.

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: Apparatus and techniques are disclosed for aligning the operation of the ink jet printhead cartridges of a multiple printhead ink jet swath printer that includes a print carriage that is movable along a horizontal carriage scan axis, (b) first and second ink jet printhead cartridges supported by the movable carriage for printing onto a print media that is selectively movable along a vertical media scan axis, and (c) an optical sensor supported by the movable carriage.

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: The device ascertains existence of a small inkdrop to be ejected from a thermal-inkjet pen. It includes a light source (preferably a nonpoint source with extended threadlike form perpendicular to the light path), detector, and optical element--preferably a cylindrical lens--for passing light from source to detector through an inkdrop probe volume, and for causing that light to be concentrated near the detector. Along a segment of the light path near the detector, the light is concentrated into a cross-section which is much smaller than that of the probe volume and is, within that segment, approximately independent of position along the path.

Abstract: An ink jet recording apparatus of the continuous jet type wherein the position of an ink jet jetting axis or nozzle axis can be detected readily with a simplified construction. The ink jet recording apparatus comprises test signal generating means which generates a controlling signal which varies continuously. Switch means selectively couples one of recording signal generating means and the test signal generating means to a controlling electrode of charging means provided for charging an ink drop. An electrically isolated conductive drop catcher catches an ink drop which has passed by separating means for forming an ink jet, and current detecting means detects electric charge carried to the conductive drop catcher by charged ink drops as an electric current. Relative position detecting means measures a relative positional relationship between an ink jet flying axis and the separating means from a controlling voltage outputted from the test signal generating means and an output of the current detecting means.