Abstract: A printer communication system includes a printer (20) having a printer controller (34) with memory (38) and a processor (36). The printer (20) receives and transmits information through a port (40) to which a host computer (10) is coupled. The printer controller (34) may be programmed to be operable to receive configuration-related commands through the port (40), process the configuration-related commands received by the port immediately provided that a command is a safe command to process while the printer (20) is busy processing a print job. The printer (20) may respond to the host computer (10) by indicating that the change was successful or that the printer (20) must be taken offline before the change may be made. The printer controller (34) is programmed to be remotely taken offline and put back online. A symbol set list command may be used by printer (20) to send symbol sets to host computer (10).

Abstract: An ink supply and delivery system for a printer cartridge including a printer cartridge having an interior, at least one air inlet to the interior, and at least one ink outlet from the interior. An air pump is connected to the air inlet of the printer cartridge and creates a positive pressure in the interior of the printer cartridge. The system further includes an ink source, including ink, in the interior of the printer cartridge, the ink source in fluid communication with the ink outlet of the printer cartridge whereby the positive pressure created by the air pump in the interior of printer cartridge forces ink to flow from the ink source in the interior of the printer cartridge through the ink outlet. The ink source is preferably in a resilient container, and the system alternately includes a resilient air container either within, next to, or encapsulating the resilient container of the ink source.

Abstract: A method of performing interlace printing on a print medium with a printhead of an ink jet printer includes providing an array of pixel locations on the print medium. Each pixel location has a common maximum number M of ink drops that the pixel location may receive. Each pixel location is assigned a respective desired number D of ink drops which are to be placed at the pixel location. Each desired number D is less than or equal to M. Sets of threshold values are created. A number N of the sets of threshold values is equal to or greater than M. Each of the pixel locations corresponds to one of the threshold values of each set of threshold values. A respective, single ink drop is selectively jetted at each pixel location. Whether the single ink drop is jetted onto a respective pixel location is dependent upon the desired number D assigned to the respective pixel location and the corresponding threshold value of one of the sets of threshold values.

Abstract: A device and method of determining an amount of ink to be used to print a color of a particular color lightness, chroma and hue in an inkjet printer in which the color lightness, chroma and hue are measured for a full ink wedge and a reduced ink wedge for a given color. The full ink wedge uses the maximum amount of ink for the given color and causes bleed through or smearing to occur and the reduced ink wedge uses less than the maximum amount of ink for the given color. A color difference between the reduced ink wedge and the full ink wedge is calculated. A vector distance between the reduced ink wedge and a white point in a three-dimensional colorant space is then calculated. Calibration points for each colorant or colorant combination in a three-dimensional colorant space are determined based on the vector distance, the color difference, and the predetermined color tolerance. A printer profile table is then generated using these new calibration points and downloaded to the printer.

Abstract: Method and apparatus for controlling a sheet feeder assembly for an imaging apparatus, the sheet feeder assembly including a motor coupled to a gear train for applying a rotational force to a sheet picker roller, a media supply tray for holding a media stack having a plurality of media sheets, and a buckler for buckling a top sheet of print media to separate the top sheet from the media stack, the method including the steps of driving the sheet picker roller at a initial velocity until a backlash of the gear train is eliminated and/or the top sheet has been buckled; and thereafter, accelerating the sheet picker roller from the initial velocity to a target velocity using selectable sheet picker roller velocity profiles.

Abstract: A system identifies faulty ink jet nozzles among a plurality of ink jet nozzles in an ink jet print head based on evaluation of a test pattern printed by the print head. The printed test pattern consists of test images, where each of the test images is printed by a corresponding one of the plurality of ink jet nozzles. The test images occupy locations within the test pattern indicated by location coordinates. The test pattern is visually inspected to identify empty locations within the test pattern, where an empty location is a location in the test pattern not occupied by a test image. The empty locations are designated according to the location coordinates of the empty locations. The location coordinates of the empty locations are then correlated to ink jet nozzles that, if functioning properly, would have printed test images at the empty locations. The ink jet nozzles that, if functioning properly, would have printed test images at the empty locations are designated as faulty.

Abstract: An apparatus and method is provided for compensating for the effects of thermally induced droplet size variations in ink-jet printers. The apparatus includes a temperature determination unit for determining the temperature of the print head, and a halftone adjustment unit configured to receive the print head temperature from the temperature determination unit and to receive image data in the form of nominal halftone values. The adjustment unit can increase or decrease the number of dots to be printed, and thereby compensate for droplet size variations, either by adjusting the nominal halftone values based upon the temperature or by adjusting a threshold array based upon the temperature. The temperature determination unit can predict the print head temperature by counting the number of dots to be printed by counting the binary halftone values fed to the swath memory.

Abstract: A binary printer for printing halftone color images on a substrate so that the determination of whether to print a dot or to not print a dot of each color ink at each pixel location is based at least in part upon an estimated temperature of the print head. The temperature of the print head may be estimated based upon direct measurement of the ambient temperature and/or direct measurement of temperature of some portion of the print head. Alternatively, the temperature of the print head may be estimated by counting the number of dots fired by the print head.

Abstract: An ink jet printer is provided comprising a housing, an ink jet printing apparatus and a coating apparatus. The ink jet printing apparatus is located within the housing and includes an ink jet printing device capable of ejecting ink droplets onto a first side of a printing substrate which moves through the housing along a printing substrate feed path. The coating apparatus is positioned along the printing substrate feed path and spaced from the printing device. The coating apparatus applies a substantially uniform layer of coating material onto at least a portion of the first side of the printing substrate.

Abstract: A device and method of printing a color image using a lookup table that indicates the amount of at least two concentrations of a given ink color to use. Initially, several color wedges made from uniformly distributed digital counts for each color from lightest to darkest are printed. The color lightness value for each wedge is then measured as an L* value of the CIELAB system along with a granularity value. An interpolation process is then performed to determine the color lightness values and granularity values for color values between wedges. A diluted ink minimum color lightness point is identified by determining the darkest color that can be generated using only diluted ink. Ink patterns are then selected using only diluted ink for color lightness values lighter than the diluted ink minimum lightness point in the lookup table. A zero diluted ink starting point is then identified by determining that granularity improvement cannot be achieved significantly when adding more diluted ink to a pixel matrix.

Abstract: Apparatus and method controls and varies a spacing between multiple print elements, such as ink jet print orifices, in a printing system. A signal representing at least one of an advance speed of a print medium in a feed direction in the printing system and an approximate drying time of an ink after being applied to the print medium is supplied to a controller. A device, responsive to the controller, varies the spacing between at least two print elements on the basis of at least one of the advance speed of the print medium and the approximate drying time of the ink.

Abstract: An ink jet print head identification system for providing print head identifying information to the electronics of an ink jet printer includes one or more parallel load, serial out, dynamic shift registers integrated into a print head chip having a plurality of address lines interconnecting the printer electronics and the print head electronics. The memory input of each shift register is electrically connected to a memory matrix that supplies digital bits of information to the shift register in response to receiving a decode signal function from the printer electronics. In a preferred embodiment, two of the address lines provide each of the registers with successive sequential clock signals to serially shift the bit of information received from the shift register's corresponding memory matrix to an output line where the print head identifying information is read by the printer electronics.

Abstract: A container having a fixed volume sealed from the atmosphere by an elastic septum is filled with liquid via a needle inserted through the septum, the needle providing a path for liquid flow into the fixed volume from an external source through the septum and a path for air flow from the fixed volume to atmosphere through the septum. The needle includes a stem having a hollow tube with a non-cylindrical section and a cover element cooperating with the non-cylindrical section of the tube to form an air passage and give the stem a cylindrical configuration even in the region of the non-cylindrical section of the tube. The configuration of the stem minimizes damage to the septum as the stem is inserted through or withdrawn from a septum, while the air passage permits air to exit from the container through the stem as liquid enters the container through the tube.

Abstract: A system and method for supplying ink to a print head on a moving carrier using the acceleration of the print head carrier to assist in pumping the ink. The system includes an ink supply reservoir and an ink pump on the moving carrier where the ink pump has a carrier reservoir including at least one flexible wall that deforms from inertial resistance to acceleration of the moving carrier, a print head, and a pressure regulator in fluid communication with the carrier reservoir and the print head. The system also has an ink supply tube in fluid communication with the ink supply reservoir and the carrier reservoir such that acceleration of the moving carrier and ink pump deforms the flexible wall and thereby pumps ink from the ink supply reservoir to the carrier reservoir and from the carrier reservoir to the print head, or solely to the carrier reservoir.

Abstract: A system and method for controlling a stepper motor wherein the amount of memory space needed to store a phase table is minimized. The stepper motor controller comprises a memory sized to store data representing a plurality of states for current outputs to be supplied to a first winding of a stepper motor and from which are derived current outputs for the first winding and a second winding of the stepper motor. A finite state machine is coupled to the memory. The finite state machine comprises a first address register that stores an address for data in the memory for a present state of the first winding and a second register that stores an address for data in the memory for a present state of the second winding.

Abstract: Mechanical and electrical characteristics of individual print cartridges are determined and used to generate control information for customizing control of each individual print cartridge. One or more characteristics including nozzle heater resistance, drop mass and drop velocity for individual print cartridges are determined and used to derive offset values for widths of pulses used to drive nozzle heaters in the individual print cartridges. While all three characteristics are preferably used, any one or two may also be used. Once determined, pulsewidths or offsets from nominal pulsewidths to improve or optimize printing using the print cartridges are stored in memory devices located on the print cartridges so that printers utilizing the print cartridges can retrieve the pulsewidth or offset data and utilize it in customizing or individualizing control of the print cartridges.

Abstract: A method of converting a first set of input color values, such as RGB color values, into a set of device colorants, such as CMY color values, includes the step of providing a look-up table associating a respective, predetermined set of CMY color values with each of a plurality of selected sets of RGB color values. The first set of RGB color values includes a first red color value, a first green color value and a first blue color value. A first random number is added to the first red color value to obtain a randomized red color value. A second random number is added to the first green color value to obtain a randomized green color value. A third random number is added to the first blue color value to obtain a randomized blue color value. Each of the randomized red color value, the randomized green color value and the randomized blue color value are compiled together to obtain a set of randomized RGB color values.

Abstract: An improved printer is provided in which one of the "built-in" resident fonts can be effectively replaced by downloading from a host computer (into either Flash memory or the printer's hard disk drive) new or modified data under the same font descriptor as the built-in font. After the replacement font has been received by the printer and stored into a non-volatile memory storage device, the user can choose whether to use the replacement font or the built-in font for a particular document, by use of a printer setting named the "Font Priority." This Font Priority setting has the values of either "Resident" or "Flash/Disk." When the Font Priority setting is set to "Resident," the printer preserves Adobe compatibility by having the PostScript interpreter search the virtual memory first to locate a font that is requested by a print job. If the particular font is found, no other font memory storage device is searched and the copy of the font reference in the virtual memory is selected.

Abstract: Methods and apparatus for using isochronous data transfer mode to communicate between a host computer and a printer. Preferably, the printer receives a sufficient volume of data from the host, such as a computer, over an isochronous communications channel, to begin but not complete one print pass (i.e., line scan or page scan). Subsequently, the print pass is initiated causing a print mechanism to move a printing device relative to a substrate without interruption. Thereafter, sufficient data to complete the pass without interruption is received over the isochronous communications channel during the print pass. The high speed transfer rates afforded by isochronous data transfer allow for printing to be initiated before all of the data necessary to complete a print operation without interruption is received. Moreover, the size of a printer buffer used to store the print data before printing may be considerably reduced to store only a portion of the data needed for an entire print pass.

Abstract: An ink jet printer for printing on a print medium includes a paper transport assembly with a plurality of rolls defining an approach path to a printing area and a return path from a printing area. A printhead positioned in the printing area is configured for jetting ink at selected locations on the print medium. A print medium heating assembly includes a heated roll, a first backup roll and a second backup roll. The heated roll and the first backup roll define a first nip therebetween and the heated roll and the second backup roll define a second nip therebetween. The first nip is positioned in association with the aproach path and the second nip is positioned in association with the return path.