Abstract: This invention provides an improved ink flow path between an ink reservoir and vaporization chambers in an inkjet printhead. In the preferred embodiment, a barrier layer containing ink channels and vaporization chambers is located between a rectangular substrate and a nozzle member containing an array of orifices. The substrate contains two linear arrays of heater elements, and each orifice in the nozzle member is associated with a vaporization chamber and heater element. The ink channels in the barrier layer have ink entrances generally running along two opposite edges of the substrate so that ink flowing around the edges of the substrate gain access to the ink channels and to the vaporization chambers.

Abstract: A thermal transfer printing is carried out in a printer. A cassette case housing a thermal transfer printing film is inserted into the printer and set in position. The cassette case has an outer surface provided with a plurality of marking positions to one of which a reflective mark is applied to indicate the usage and/or ink characteristics of the printing film in the cassette case. For printing, printing sheets are fed into the printer. Each sheet has a sheet mark indicating the usage and/or ink characteristics adapted to it. The reflective mark and the sheet mark are detected in the printer, and only when it is determined that the detected marks are of the same usage and/or of the same ink characteristics, the printer is allowed to operate.

Abstract: A multiple printhead cartridge color thermal ink jet printer having apparatus for measuring the offsets between the multiple printhead cartridges each of which includes a nozzle array of one or more columns of nozzles, each column being parallel to the media axis of the printer. The cartridges are individually operated, stationarily and while scanning, to fire drops at an aperture plate interposed between an optical drop detector and the nozzle arrays of the printhead cartridges. The detection of drops passing through the aperture plate and the non-detection of drops blocked by the aperture plate provide information which is utilized in conjunction with the nature of the operation of the cartridges that produced the detected drops to determine the positions of the nozzle arrays of the cartridges relative to each other.

Abstract: An ink-jet ink comprises a colorant and a liquid phase consisting essentially of polymerizable monomers. For continuous printing, the ink also includes a conductive component that is soluble in the liquid phase. No methanol, ethanol, MEK or other such low molecular weight organic solvent is required.

Abstract: An image bar recording system, which, in a preferred embodiment, utilizes an LED image bar, with associated circuitry for recognizing which of individual LEDs comprising the print bar are out of registration in the slow scan, process direction of a moving photoreceptor upon which the image is to be recorded. Modification of the drive circuits to the individual LEDs results in energization signals being delayed to the identified, misregistered LEDs resulting in an exposure line which is in correct slow scan registration.According to another aspect of the invention, the delayed signals are selectively applied to intentionally cause a misregistered exposure line when using the image bar in conjunction with a raster output scan system.

Abstract: A precision belt hole sensor and associated conditioning circuitry provides precise trigger signals that enable synchronous printing in a color printer. An image bar recording system, which, in a preferred embodiment, utilizes a plurality of LED image bars, forms a plurality of latent images on a moving photoreceptor which may subsequently be developed in different colors. A pair of sensors associated with each printbar views illuminated pixels at the end of a printbar, through a pair of oppositely aligned photoreceptor holes. The signals detected by the sensor are amplified and processed to provide inputs to a comparitor circuit which generates an output signal at a time which precisely defines the passage of the trailing edge of the hole, past the sensors. The signal from the comparitor is used to accomplish skew registration of the printbar and to provide sync signals to enable precise formation of the leading edge of the associated image frame.

Abstract: A method for forming an image on a dye. The dye absorbing visible light of a first wavelength, but not visible light of a second wavelength. The dye is decolorized when visible light of the first and second wavelength irradiate the dye simultaneously. Decolorization will be effected only if visible light of the first wavelength and visible light of the second wavelength are simultaneously applied. The method utilizes lasers as the source of the visible light of the first and second wavelengths; thus insuring formation of high resolution images.

Abstract: A method for multiplying the speed-resolution product of a raster scanning or imaging device such as an inkjet printer, and a resulting pixel image data structure, are disclosed. Illustratively, a 300-dot per inch (dpi) by 600-dpi logical pixel image is mapped to a corresponding, non-overlapping physical dot image, and the printer's inkjets are fired responsive to the dot image to direct generally spherical ink droplets onto paper at 600-dpi resolution grid timing in order effectively to double the horizontal resolution of the printed pixel image, without increasing the firing rate of the print head. In order to accomplish this, and to avoid ink dot overlap, the printable pixel image is thinned before it is printed by a method that leaves no visible horizontal or vertical gaps by selectively turning off pixels within a `black` image that were on and that otherwise would result in ink dot overlap and slower print head speeds were the inkjets cycled at 600-dpi resolution timing.

Abstract: The Ionographic Beam Positioning And Crosstalk Correction Using Grey Levels is a method and apparatus which solves the problem of poor density and definition of an image formed by an ion current (20) projected from an ionographic print head (10), caused by electric field crosstalk between adjacent modulation electrodes (22) in the head (10). By applying a partial modulation voltage (V.sub.M ') to the adjacent modulation electrodes (22), the density of an individual pixel charge is increased and the pixel charge is "addressed" or deflected to a position on a receptor surface (26) more precise than the pitch dimension between modulation electrodes (22). A data processor (46) intercepts printing driver commands (44) and constructs therefrom values of partial modulation voltage (V.sub.M ') by means of an algorithm making deliberate use of the crosstalk phenomenon. The algorithm is pre-defined with respect to image-dependent modulation voltage states and implemented as programmed software or firmware.

Abstract: A normally solid recording material is heat-melted in a path defined by a nozzle leading to an ejection outlet and is imparted with a thermal energy from a heater corresponding to a recording signal to generate a bubble. As a result, a droplet of the recording material is ejected out of the ejection outlet under the action of the bubble while the bubble is caused to communicate with ambience. The normally solid recording material preferably contains a colorant, a first heat-fusible solid substance having a melting point Tm of 36.degree.-150.degree. C. and a boiling point Tb of 150.degree.-370.degree. C., and a second heat-fusible solid substance having a melting point Tm and a solidifying point Tf satisfying a relationship of Tm-Tf.ltoreq.30.degree. C. The distance between the heater and the ejection outlet, the sectional size of the nozzle and the thermal energy imparted by the heater are controlled to cause the bubble to communicate with ambience.

Abstract: A heating elements' row provided in the thermal head is separated into at least three blocks each including a plurality of heating elements. When each heating element is heated by turning on electricity, the last heat accumulation amount of said each heating element is calculated, as well the last sum of heat accumulation amounts in each block is calculated. And, the calculated amount of the sum of the heat accumulation amounts in each block is corrected in accordance with the position of each block in the heating elements' row. Subsequently, the time period for turning on electricity to each heating element is determined based on said calculated amount of last heat accumulation amount of said each heating element and said corrected amount of last sum of heat accumulation amount of each block, thereby adequate control of time period for turning on electricity can be performed so as to response to actual heat accumulation condition in each heating element.

Abstract: Thermal transfer recording is improved by a recording method involving providing a thermal transfer material having a support and an ink layer disposed thereon and which in turn includes a binder and a colorant. The binder includes 45-70 wt. % of an ethylene-vinyl acetate copolymer, 25-50 wt. % of a wax, and 7-12 wt. % of a tackifier based on a total weight of the binder. The ink layer has a breakdown strength of 30-80 kg/cm.sup.2 at 25.degree. C. The method also involves contacting an ink layer side of the thermal transfer material with a recording medium, supplying a pattern of energy from a recording head to the thermal transfer material, and separating the thermal transfer material from the recording medium to leave a transferred image on the recording medium.

Abstract: A method of driving an ink jet type printing head is applied to a printing head which has a plurality of channels, a plurality of nozzles provided on ends of the channels and a plurality of piezoelectric elements for varying volumes of the channels in response to driving voltages so as to eject ink from each nozzle having a corresponding channel the volume of which is reduced by a corresponding one of the piezoelectric elements. The method includes the steps of applying a first driving voltage to a first group of piezoelectric elements and a second driving voltage to a second group of piezoelectric elements, and controlling a phase of at least one of the first and second driving voltages so that a predetermined phase difference exists between the first driving voltage and the second driving voltage.

Abstract: In a piezoelectric ink jet printer head having a laminated piezoelectric layer, actuating voltage is applied between only electrodes corresponding to a selected jetting device. A part of the piezoelectric ceramic layers between the electrodes is deformed in accordance with a slip effect, to jet ink from the selected jetting device. Since the polarization direction of the piezoelectric ceramic layers is almost perfectly perpendicular to the direction of an actuating electric field, the actuating voltage can be reduced. Further, piezoelectric ceramic layers can be stacked to obtain the necessary strength of a laminated piezoelectric element without decreasing the displacement amount. Thus, the reliability of the laminated piezoelectric element is enhanced. Moreover, the insulation of the electrodes is not deteriorated by a short circuit, migration of silver or the like. Such properties as durability and moisture resistance are also enhanced.

Abstract: An ink jet recording method of applying, to a piezoelectric element serving as an energy generating member for ink droplet formation and emission, a first voltage pulse for retracting the meniscus in a direction opposite to the emitting direction prior to the ink droplet formation, and a second voltage pulse supplied in succession to the first voltage pulse for emitting an ink droplet. The first voltage pulse is controlled according to the circumferential temperature of the piezoelectric element in action.

Abstract: A chart recorder (10) is disclosed having an automatic paper loading system, an automatic tensioning system and an "odometer" system for determining the amount of paper moved through the chart recorder. The chart recorder (10) includes a print roller (34) and a feed roller (22), both in frictional contact with the paper in the recorder and both connected to and rotated by a motor. The feed roller (22) is connected to the motor through a one way clutch that allows the feed roller (22) to "free wheel" when the feed roller (22) is rotated at a faster rate, due to frictional contact with the paper, than the roller would be rotated by the motor (56). Dissipative forces in the one way clutch (68) and bearings (24) of the feed roller (22) cause it to resist being rotated which imparts tension to the paper and draws it into contact with a paper guide (14).

Abstract: An information recording medium comprises a recording layer including a mixture of organic polysilane and oxo metallic phthalocyanine pigment. Information is recorded by adding heat or light to the recording layer. In a method for recording information onto the information recording medium, a decoloring reaction of oxo metallic phthalocyanine pigment is used which is caused by heating the recording layer to a temperature equal to or higher than a pyrolyzing point of organic polysilane.

Abstract: There is disclosed a method for providing precise color-to-color registration of color dots in a multicolor proof with a thermal printer comprising a CPU and Printer Controller, a Motion Controller, a writing drum, and a writing head coupled to a translation means. Using the disclosed method, a proof and a dye donor member with a predetermined dye color thereon are mounted on the writing drum. The writing head is then moved to a predetermined start position defined by a sensor at a predetermined position along the translation means which has its optical path blocked by the writing head. The writing head is then moved forward to a predetermined home position which is defined by a next subsequent pulse from a multi-pulse radial position-indicating encoder coupled to the translation means occurring after the writing head leaves the start position.

Abstract: A method of monitoring and controlling the quality of pen markings on a plotting medium by qualifying each pen based on optically sensing across a sample line drawn on an actual medium. During each subsequent plotting task of a particular pen which has been qualified, an actual line plot is optically sensed across a selected point to make a comparison with the sample line. If the actual line plot is unsatisfactory, the deficient pen is replaced and the plot is restarted from the beginning, or retraced from the last good verification, or is stopped to allow the user to select an appropriate corrective procedure.

Abstract: According to the present invention, there is disclosed a capping device for an ink jet printer which is constructed such that a cap supporting member 14, adapted to move from the non-capping position to the capping position by the thrust action of a carriage 3, is arranged on the home position side of the ink jet printer so that the outer end part of the cap supporting member 14 is displaced toward the nozzle surface of a printing head 4 with the aid of a guide surface 15b having an inclined surface 15a, until a cap 5 on the cap supporting member 14 is brought into close contact with the nozzle surface of the printing head 4 with an adequate intensity of thrust force by means of a turnable lever 8 operatively connected to the inner end of the cap supporting member 14, while resilient force of a cap spring 11 is exerted on the base end part of the turnable lever 8 so as to normally bias the cap supporting member 14 in the direction toward the printing head 4.

Abstract: An image is recorded on a transparent heat sensitive material having a transparent support and a transparent heat sensitive layer disposed on the transparent support. The transparent heat sensitive material is moved in an auxiliary scanning direction. Image information is recorded on the transparent heat sensitive material in a main scanning direction substantially normal to the auxiliary scanning direction with a thermal head having an array of as many heating elements as the number of pixels along the main scanning direction, so that the transparent heat sensitive material is two-dimensionally scanned to record an image in an image area thereon. A non-image area of the heat sensitive material other than the image area thereof is recorded at a predetermined density level. The array of heating elements has a length larger than the width of the transparent heat sensitive material in the main scanning direction, so that the entire surface of the non-image area can be recorded at the predetermined density level.

Abstract: A serial recording apparatus for reciprocating a recording head with respect to a recording medium to perform bidirectional recording includes a position detector for detecting a reference position of the recording head, a driving unit for reciprocating the recording head within a predetermined area including the reference position, a calculating unit for calculating a difference between reference positions detected by the position detector by reciprocal movement when the recording head is reciprocated by the driving unit within the predetermined area, and a correcting unit for correcting a positional error in bidirectional recording on the basis of the difference calculated by the calculating unit.

Abstract: A one-step process bonds a manifold to a printhead die and interconnection board located on a heat sinking substrate, encapsulates wire bonds extending from the interconnection board and the printhead die, and seals air gaps between the manifold and printhead die. A through hole is made in the heat sink substrate and communicates with a cavity defined by the manifold. During assembly, the manifold is positioned on top of the substrate containing the printhead die and the interconnection board and retained by pins. An encapsulation fluid is injected from an underside of the substrate through the through hole and into the cavity. Injection is stopped when the fluid flows nearly to the front of the printhead. The process provides encapsulation of wire bonds, sealing of any air gap between the manifold and the printhead along a front face, and enhances structural bonding of the manifold to printhead components.

Abstract: Impulse ink jet apparatus has a plurality of side-by-side chambers extending along a line that is slanted with respect to a direction of scanning relative to a recording medium. Each of the chambers includes a plurality of orifices that are arranged along a line extending substantially transverse to the scanning direction and a transducer for ejecting a plurality of droplets from the orifices of each chamber. The orifices are formed upon an orifice plate such that the distance between the centers of adjacent orifices associated with a single chamber are separated by a predetermined distance greater than the center distance required for drop placement on the recording medium.

Abstract: A system for compensating for motion errors that degrade image quality by modifying the modulation of a scanning beam across a photosensitive surface in response to changes in speed of the photosensitive surface by use of a shaft encoder mounted adjacent to the photosensitive surface to determine the speed of the photosensitive surface, a comparator electrically connected to the sensor for determining the change of speed of the photosensitive surface in relation to a standard speed, a converter connected to the comparator and responsive to the change in speed to provide a signal representing an image quality factor, and for altering the modulation of the beam of the scanning system in relation to the speed of the photosensitive surface.

Abstract: In an image-forming system where a photosensitive belt is exposed to and scanned with a laser beam to form an image on the surface of the photosensitive belt, a standard pattern having laser beam-transmitting portions and non-transmitting portions arranged alternately in the direction of main scanning of the laser beam is formed on the photosensitive belt, and light-detecting means is disposed to detect the intensity of the laser beam transmitted through the transmitting portions. Dislocation of the focal point of the laser beam is detected based on the difference of the detected beam intensity between the transmitting portions and the non-transmitting portions, and based on the result of this detection, a collimator lens is moved in the direction of the optical axis to correct the dislocation of the focal point.

Abstract: An ink jet recording process employing an ink which comprises a liquid medium containing at least water and an organic solvent and containing therein a water-soluble dye selected from the group consisting of a solubilized vat dye, a solubilized sulfur dye, a leuco salt of a vat dye, and a leuco salt of a sulfur dye. In one embodiment of the invention, the ink can be fixed on a recording medium by oxidation, and is suitable for ink-jet printing.

Abstract: A perfecting printer for performing a double-face printing operation of printing images on obverse and reverse faces of at least one sheet on the basis of a series of print data input from an external device and a method for controlling the double-face printing operation of the printer. The perfecting printer includes a page memory having an empty area for storing a series of print data for the obverse and reverse faces of the sheet input from external device, and a control unit for judging as to whether the empty area is no longer available in the page memory while the series of print data are being stored into the page memory and forcibly printing print data for the obverse face of the sheet on the sheet when it is judged that the empty area is no longer available in the page memory and that only the print data for the obverse face of the sheet are completely stored in the page memory.

Abstract: A high-speed printing method capable of considerably reducing a printing time consumption in a color video printer having at least one line memory coupled to receive at least one line data indicative of a given color image from a video memory, and provided with a plurality of gradation data corresponding to a respective color component, comprising the steps of searching the largest value of one line data out of the line memory, of designating the largest value as a maximum value of heating gradation relative to the one line data, and of terminating one cycle of printing operation for the one line data when reaching the maximum value of the heating gradation, irrespectively of a total heating gradation number.

Abstract: Fluorescent ink compositions and methods for using the ink co positions in drop-on-demand ink jet printers is provided. The fluorescent ink compositions are formulated with an aromatic alcohol, a glycol, a fatty acid, and at least one fluorescent pigment.

Abstract: A recording liquid containing a dye, glycerine, an aliphatic monohydric alcohol and water. The dye is a mixture of C.I. Food Black 2 and at least one compound selected from compounds which are represented by the following general formulas [I] and [II]: ##STR1## [where Q1 is a phenyl group or a naphthyl group which are substituted by a lower alkyl carbonylamino group and a lower alkoxy group or a naphthyl group substituted by a SO.sub.3 M group, Q2 is a naphthyl group substituted by a SO.sub.3 M group or a phenyl group substituted by a lower alkoxy group, Q3 is a phenyl group, a naphthyl group, or a phenyl group or a naphthyl group which are substituted by a SO.sub.3 M group, R.sub.1 and R.sub.2 are each a lower alkyl group, a lower alkoxy group or a lower alkyl carbonylamino group, R.sub.3 is a hydrogen or a phenyl group substituted by a SO.sub.3 M group, n is 0 or 1, and M is an alkaline metal or an ammonium cation.

Abstract: A printing assembly having a guiding and driving system for moving an article past ink emission nozzles. A detecting device detects the movement of the article through the assembly and based on that detection triggers emission of ink by the nozzles. Compressed air jets are forced toward the article, creating suction due to the Bernoulli effect which effectively maintains the article a set distance from the nozzles.

Abstract: A method and apparatus for recording an information signal on the recording layer of an optical record carrier by writing areas of modified optical properties in such layer. The layer is heated locally to a temperature above the write temperature by scanning with a laser beam whose power (P) is pulsed between a low level (Pl) and a write level (Ps) in accordance with the information signal. A signal (.alpha.(t)) which is indicative of the speed with which the write areas are formed, and therefore of the dimensions of such areas, is derived by a measurement circuit (50) from the radiation reflected from the recording layer. The measurement circuit is part of an adjustment circuit (12) which also includes a control circuit (60) which derives an adjustment signal (Ih) for a laser drive circuit (13) to control the write power (Ps) of the laser beam in accordance with the area forming-speed signal (.alpha.).

Abstract: Apparatus for protecting optical elements of an optical ink drop detector that detects the presence of an ink drop in a drop detection zone, and for maintaining an aperture plate used in conjunction with the ink drop detector. The apparatus includes a movable plate having an apertured region and a non-apertured region. The plate is movable relative to the optical elements of the drop detector and is configured to have the aperture region adjacent a drop detection zone of the optical ink drop detector when in a first position and to have the non-apertured region adjacent the detection zone when in a second position. Cleaning brushes are provided for cleaning ink from the aperture region of the movable plate when the plate is moved between the first and second positions, and an enclosure is provided for enclosing the aperture region of the plate when said plate is in the second position.

Abstract: A multi-color, electrostatic, laser printing system employs a method for enhancing color representations at boundaries of pixels with different colors. The system employs a charged electrostatic surface that is selectively discharged by application of a modulated laser beam. The system performs the steps of: identifying a pixel of a first color that bounds a pixel of a second color, the first color being a secondary color; decreasing applied laser power to the electrostatic surface at the secondary color pixel site in the process of applying underprint and overprint toners to produce the secondary color; and inhibiting the decrease of applied laser power when applying the overprint toner if the second color pixel is a primary color that is the same as the color of the overprint toner of the secondary color pixel. A similar inhibition action occurs when an isolated primary color pixel or a thin pixel line is found so as to assure proper development.

Abstract: An image processing apparatus for recording image data using an ink jet recording method comprises: an ink jet nozzle to eject an ink droplet and deposit onto a paper; a controller to control the ink jet nozzle so as to enable the recording interval when the ink droplet is deposited on the same position on the paper a plurality of times; a supply circuit to supply image data to the ink jet nozzle; and a distinction circuit to discriminate whether the input image data is a half tone image or a diagram image, wherein this controller controls the recording interval in accordance with the result of the discrimination. With this apparatus, by superposing the recording dots on the same position on the paper in accordance with the binary image data, gradations and graininess can be improved by a simple structure.

Abstract: A method employing multiple pulses per pixel to reproduce an image. A motion detector detects movement of an image receptor relative to a row of reproduction elements. The motion detector generates multiple pulses for each movement of the image receptor corresponding to a pixel dimension. Each pulse from the motion detector enables each reproduction element for a predetermined time.

Abstract: A method of detecting an ink residual quantity in an ink jet printer, which is capable of eliminating a possibility of blank printing even when effecting a print on the large-sized paper by detecting the ink residual quantity at a high frequency and of keeping a good printing efficiency. The ink residual quantity is detected in an equispeed motion area of the carriage. The ink residual quantity can be stably detected per line without stopping the carriage and providing a special liquid level oscillation preventive mechanism.

Abstract: An ink-jet textile printing ink, comprising from 5% to 30% by weight of a reactive dye having at least one of a monochlorotriazine group and a vinyl sulfone group, and a water-based liquid medium, wherein said liquid medium comprises from 1% to 50% by weight of thiodiglycol and from 2% to 45% by weight of at least one organic solvent selected from a di-, tri-, or tetramer of oxyethylene, a di-, tri-, or tetramer of oxypropylene, and a mono- or di-C.sub.1 -C.sub.4 -alkyl ether of any of these di-, tri- or tetramers.

Abstract: Apparatus and techniques are disclosed for aligning the operation of the ink jet printheads of a multiple printhead ink jet swath printer, and particularly for aligning the operation of the printheads along the carriage scan axis. The relative positions of vertical test line segments printed by the cartridges at a fixed swath position are determined with an optical sensor. The relative position information is utilized to calculate horizontal alignment corrections for the printhead cartridges which are utilized to adjust the horizontal offset shifts provided for the swath data and to adjust the timing of the firing of the ink jet nozzles of the printhead cartridges.

Abstract: An image forming apparatus having a quantum-well semiconductor laser as a light source, a photosensitive member and an optical system for transmitting a laser beam emitted from said quantum-well semiconductor laser to the photosensitive member. The optical system has a reduced transmittance to suppress variations in the laser beam intensity within an allowable range. The transmittance of the optical system is adjusted by providing a reflecting coating on the beam emitting surface of the quantum-well semiconductor laser.

Abstract: An ink-jet recording process, recording unit, ink cartridge, and ink-jet recording apparatus employing ink that comprises a triol consisting of carbon atoms, hydrogen atoms and hydroxyl groups, and wherein the triol is selected from the group consisting of the following (a) to (c):(a) a straight-chain triol having 5 carbon atoms;(b) a compound of the formula ##STR1## wherein any three of A.sub.1 to A.sub.5 each represent a hydroxyl group, and the remaining two each represent a hydrogen atom, or a branched triol having 6 carbon atoms; and(c) a triol having at least 7 carbon atoms.

Abstract: An optical recording medium for optical data recording and reproduction is produced through a process including the steps of forming an optical recording layer comprising an organic film on a substrate and irradiating the organic film with laser light to scatter the irradiated portion of the organic film, thus forming a tracking groove thereat and leaving an optical recording part along the tracking groove. The thus formed optical recording part and tracking groove provide a high reflectivity ratio or a high reflective contrast, whereby a good tracking fidelity is ensured during the optical recording and reproduction.

Abstract: An improved method and apparatus for grey level printing using linear arrays of LED's or the like are described. In one embodiment, a circuit is provided that includes a look-up table that compares for each pixel to be printed a time-changing count from a threshold counter with a multibit signal representing a grey level value. In accordance with the program in the look-up table, a two-bit signal is fed to the printhead and used to turn the LED on at an intensity level commensurate with the two-bit signal. This process is repeated many times to determine the "on" time or pulsewidth of the LED for that pixel. With each repetition, a new two-bit signal is generated to define intensity level. In another embodiment, the number of repetitions of this process are shown to be substantially reducible by using a vernier clocking scheme involving a clock signal having different frequencies.

Abstract: A thermal transfer recording apparatus which performs image recording by causing a recording head to act on an ink sheet so as to transfer ink from the ink sheet onto recording paper. Changes in the take-up amount of the ink sheet, which is fed by being wound onto a take-up roller, are detected from changes in the amount by which the ink sheet is fed with respect to a given drive amount of an ink-sheet feeding motor, and, on the basis of the changes detected, the driving torque for the ink-sheet feeding motor is changed, thereby reducing the noise generated and the power consumed by the apparatus.

Abstract: Disclosed is an ink composition which comprises an aqueous liquid vehicle, a colorant, and a polymeric additive of the formula ##STR1## wherein R.sup.1 and R.sup.2 are independently selected from the group consisting of hydrogen, alkyl groups with from 1 to about 8 carbon atoms, and alkoxy groups with from 1 to about 8 carbon atoms, R.sup.3 and R.sup.4 are independently selected from the group consisting of alkyl groups with from 1 to about 4 carbon atoms, and x and y are each independently a number of from about 100 to about 400, present in an amount of at least about 1 part per million. The ink is suitable for use in ink jet printing processes, particularly thermal ink jet printing processes.

Abstract: A single raster scanning system (ROS) with a rotating mirror, beneficially a polygon mirror, and a single set of scan optics suitable for use in a multistation xerographic printer. A plurality of clustered laser beams from the same spatial location, but of dissimilar wavelengths, are deflected using a common mirror surface area and are subsequently separated by a plurality of optical filter. The separated laser beams are then directed onto associated photoreceptors such that their optical path lengths from the source location to their photoreceptors are substantially the same.

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. Correction of misalignment along the media scan axis is performed by adjusting the position of the nozzle array of one printhead cartridge relative to the position of the nozzle array of another printhead cartridge along the media scan axis. A movable printhead is supported on the print carriage of the printer and is moved relative to the carriage by a rotatable cam that is supported by the carriage fixedly attached to a cam lever.

Abstract: An encoder system for providing a large number of actual positional control pulses per revolution utilizes an optical digital disc. The disc is driven by the work piece transport system. A playback unit similar in construction to audio disc players can be used. The positional control information is recorded on the disc as the disc is being driven by the transport system with which the disc is to be associated. Mechanical anomalies of the drive system are compensated for in the recording process. The accuracy of the positional information is improved. The system is especially useful for high resolution ink jet printing system.

Abstract: An image recording apparatus modulates a laser beam based on an image signal and a reference clock, and then controls a polygon mirror to irradiate the laser beam on a surface of a photosensitive material. A reference clock generating circuit generates a reference clock having a frequency in proportion to a main scanning speed of a beam spot which is changed during each scanning due to a characteristic of an f.multidot..theta. lens. The reference clock generating circuit includes a line memory which has a bit per address and stores a relationship between an incident angle .theta. of the laser beam on the f.multidot..theta.