Abstract: A nip release mechanism for a fuser of a printing device includes a movable component in the printer base frame moved by opening and closing a cover, and a follower component in the fuser which follows movement of the movable component to adjust positions of a fuser pressure roll.

Abstract: A method of calibrating a multi-color electrophotographic machine having an image bearing surface includes forming toner patches of cyan, magenta, and yellow solid areas individually and in superimposed combination to form a series of single layer and multi-layer test patches. Light is emitted onto these single and multi-layer test patches. The amount of light that is reflected off of each test patch is measured. Light is also emitted onto a bare section of the image-bearing surface. The bare section has substantially no toner thereon. An amount of light that is reflected off of the bare section is measured. The step of measuring an amount of light reflected off single layer solid area test patches is repeated for a series of laser power and developer bias conditions. A laser power and/or a developer bias is adjusted dependent upon each of the three measuring steps.

Abstract: A method of setting a plurality of margins in an electrophotographic machine includes setting a top margin for a reference color black by establishing a first time delay between a vertical synchronization signal and a first line. A right margin or a left margin for the reference color black is set by establishing a second time delay between a horizontal synchronization signal and a start of printing. The other of the right margin and the left margin is set by adjusting a scan speed of a laser beam across a photoconductive element and adjusting a process speed in the cross-scan direction including the speed of the photoconductive element, image accumulation member, and print medium. A bottom margin is set by adjusting the process speed. The other three color planes, cyan, magenta and yellow are then registered or aligned to the reference color plane, black.

Abstract: The invention is directed to an ink jet printer including a printhead and a printhead driver. The printhead includes a substrate, a nozzle plate having a plurality of ink emitting orifices, a plurality of jetting heaters on the substrate and respectively associated with the plurality of ink emitting orifices, and at least one substrate heater associated with the substrate. Each of the jetting heaters and the substrate heaters include first and second terminals. The printhead driver has a plurality of energizable outputs including at least one power line output and at least two enable line outputs. One power line output is electrically connected to a first terminal of each of a jetting heater and a substrate heater. Two of the enable line outputs are coupled to a second terminal of the jetting heater and a second terminal of the substrate heater.

Abstract: A host computer transmits raster information to a multi-color ink jet printer. The printer includes a printhead connected with an electrical processor. The printhead includes a plurality of arrays of ink jetting heaters. Each array of ink jetting heaters corresponds to a different color ink to be jetted onto the print medium, and is offset relative to an adjacent array of ink jetting heaters in an advance direction of the print medium. First raster information for a first raster is transmitted from the host computer to the electrical processor of the printer. The first raster information is associated with a first array of ink jetting heaters. The print medium is printed on by selectively actuating the ink jetting heaters of the first array of ink jetting heaters, using the first raster information. After the first printing step, second raster information for a second raster is transmitted to the electrical processor. The second raster information is associated with the first array of ink jetting heaters.

Abstract: Method and apparatus for inhibiting electrically induced ink build-up on flexible, integrated circuit connecting leads, for thermal ink jet printer heads is disclosed, and relates to a thermal ink jet printer having a print head comprising an integrated circuit chip, a nozzle plate including a plurality of ink ejecting nozzles therein and overlying a heater resistor for each of the nozzles. Each of the associated heater resistors has associated active circuitry on the chip. On the chip there are a plurality of auxiliary functions requiring power, for example a substrate (silicon chip) heater, a shift register containing print head identification, fault detection circuit connections, etc.

Abstract: An improved printer is provided that uses a hard disk drive resident in the printer to temporarily store some of the page data of print jobs received by this printer. Since disk access time is relatively slow as compared to access time of random access memory (RAM), only a minimal amount of pages are initially stored on the hard disk drive while the remaining pages of a print job continue to be stored in RAM, such that the pages on the hard disk drive are interleaved with those stored in RAM. Once the pages are stored on the hard disk drive, some of the areas of RAM where they previously resided are released, which allows the printer to free up some of its RAM. In a preferred embodiment of the present invention, only every fourth page is initially stored on the hard disk drive, which effectively spreads out the effects of the slower disk access time across several pages as they are printed.

Abstract: Disclosed is an ink jet printhead apparatus for modulating drop size. Drop size modulation is achieved by providing an ink jet printhead chip for use in an ink jet printhead having a cavity in communication with a supply of ink and a nozzle. The chip includes an actuator having a first active section and a second active section. The first and second active sections are positioned at a substantially equal distance from the nozzle.

Abstract: The invention described in the specification relates to a nozzle plate for an inkjet printer including a first nozzle array having a plurality of nozzles, each of which is positioned to correspond to a desired print location, with the print location of each of the nozzles of the first array being different from one another; and a second nozzle array having a plurality of nozzles, each of which is positioned to correspond to a desired print location, with the print location of each of the nozzles of the second array corresponding to one of the print locations of the first array such that the first and second arrays each have one nozzle corresponding to each desired print location and a single ink flow path feeds ink to adjacent nozzles in each array.

Abstract: Apparatus and a method for printer size reduction moves a carrier with print element through a carrier displacement field containing two acceleration ramp area subportions on opposite sides of a print line subportion. The acceleration ramp subportions are of different lengths. A first subportion permits acceleration of the print element to substantially all of a first lower print element speed. The second subportion permits acceleration of the print element to less than substantially all of a second higher print element speed. The overall field size is reduced, but functions effectively for uni-directional printing at the first (letter mode) speed and bi-directional printing at the second (draft mode) speed.

Abstract: A sealed reservoir of an ink cartridge of an ink jet printer has one or two spring-loaded bags therein functioning as an accumulator to control back pressure within the sealed reservoir. A source of ambient air for the bag or bags also serves as a source of the air for an air bubble generator. The interior of the single bag or one of the two bags communicates with the air bubble generator so that air is supplied to the air bubble generator when air bubbles are required within the sealed reservoir to decrease back pressure therein. This same air flow arrangement from the interior of the single bag or one of the two bags permits the interior of the bag to receive ink leaking from the sealed reservoir passing through at least one capillary channel of the air bubble generator when the back pressure within the sealed reservoir becomes too low.

Abstract: An ink jet printing apparatus is provided comprising a print cartridge including a heater chip and a nozzle plate coupled to the heater chip. The heater chip has first, second, third and fourth heating elements, and the nozzle plate has a plurality of primary and secondary nozzles. The primary nozzles include first and second nozzles positioned in first and second nozzle plate columns and the secondary nozzles include third and fourth nozzles positioned in third and fourth nozzle plate columns. Each of the nozzles has one of the heating elements associated therewith for generating energy to discharge ink therefrom. The apparatus further includes a driver circuit, electrically coupled to the print cartridge, for applying firing pulses to the heating elements. The printing apparatus is selectively operable in one of a normal mode of operation and a high speed mode of operation.

Abstract: The invention is directed to a method of printing on a print medium using an ink jet printer. The ink jet printer includes a printhead assembly having a plurality of ink emitting nozzles. Ink is jetted onto the print medium from the printhead assembly during a first mode of operation using a first available set of the nozzles. Ink is jetted onto the print medium from the printhead assembly during a second mode of operation using a second available set of the nozzles, dependent upon a physical operating parameter of the ink jet printer. The second available set of nozzles has a smaller number of the nozzles than the first available set of nozzles.

Abstract: Halftoning algorithms such as error diffusion, blue noise mask, and void and cluster mask are known to produce visually pleasing, random, homogeneously distributed patterns of dots on output devices such as color displays or printers, for example. These algorithms are extended to take advantage of the mechanisms of each that cause a homogeneous distribution of dots of one colorant to produce a substantially homogeneous distribution of dots when using multiple colorants. The number of dots of each colorant are combined to form an output dot level number of dots that is caused to be substantially homogeneously distributed.

Abstract: A video frame imaging system for processing image data, including video frame data, and for printing images corresponding to print image data, comprising a computer having a processor for receiving and processing video frame data and for generating print image data and having a computer port connector, an arbitration control circuit, and a grab printer. The grab printer includes an integrated video capture unit for creating video frame data from a video input, a printer unit for printing images corresponding to print image data, and a grab printer port connector. The computer port connector and the grab printer port connector are coupled together and responsive to the arbitration control circuit to transfer video frame data created by the video capture unit between the video capture unit and the computer for processing by the computer in a first mode of operation.

Abstract: A printer having a disposable print head which contains a consumable ink supply includes the capability of determining the level of ink in the print head without directly measuring the ink supply. The print head includes a number of resistors which can be driven to an open circuit condition by the printer. The printer includes a counter and memory for tracking the usage of the print head and a driver for selectively driving the print head resistors to an open circuit condition based upon such usage. The printer is also capable of detecting the condition of the resistors on the print head and producing a resultant visual display.

Abstract: A method of printing an image on a print medium uses an ink jet printer, with the print medium being movable in an advance direction in the printer. An image area defined on the print medium includes a plurality of rasters extending in a direction transverse to the advance direction. The plurality of rasters are arranged sequentially adjacent to each other in the advance direction. A printhead includes a first array of ink jetting orifices and a second array of ink jetting orifices. Each of the first array and second array are configured for jetting a respective color ink onto the print medium. A plurality of first interlace levels associated with the first array of ink jetting orifices and a plurality of second interlace levels associated with the second array of ink jetting orifices are assigned to the plurality of rasters. Each of the first and second interlace levels are associated with only one of the rasters.

Abstract: Method and apparatus is described for detecting faults, such as cracks, in ink jet printhead heater chips using a resistor on the heater chip. The resistor is located adjacent to at least one edge of the heater chip. One method, for example, includes the steps of measuring the resistance of the resistor at a first temperature and comparing the measured electrical resistance to a theoretical calculated resistance. Another method, for example, includes the steps of measuring the resistance at a first temperature, heating the chip, and measuring the resistance at a second temperature. Faults are detected by comparing expected changes in resistance or temperature to measured changes.

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 print head electronics. Each shift register is programmed or encoded with a single digital bit. In one embodiment, a voltage pulse (load signal) received on a single chip address line by a plurality of shift registers loads the input of each encoded register with the register's own encoded bit. Two of the address lines provide each of the registers with successive sequential clock signals to serially shift the encoded information to an output device where the print head identifying information is read by the printer electronics. Other embodiments of the invention may employ any number of encoded registers independently of the number of available address lines.

Abstract: A method of printing on a print medium wherein a relocation error is induced in a paper transport system so as to randomize, bias, or redistribute harmonic errors associated with the paper transport system. The print medium is advanced in the ink jet printer in an advance direction to a registration location using the paper transport system. A first subset of an addressable set of ink emitting orifices in the printhead are used to print on the print medium at the registration location. The print medium is then moved in a reverse direction a predetermined distance. The print medium is again advanced in the advance direction and relocated at the registration location using the paper transport system. A second subset of the addressable set of ink emitting orifices in said printhead are used to print on the relocated print medium at the registration location.