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 method of printing on a print medium with an ink jet printer uses a first color ink, a second color ink and a black ink. An image area on the print medium has a plurality of pixel locations. Print image data indicate one of a presence and an absence of the first color ink, the second color ink and the black ink at the plurality of pixel locations. A subset of the print image data is defined. A determination is made as to whether the subset of print image data indicates 1) a presence of the first color ink and/or the second color ink within the subset and a presence of the black ink within the subset; 2) a presence of each of the first color ink and the second color ink within the subset at a same corresponding pixel location; and/or 3) a presence of the first color ink and/or the second color ink within the subset at a number of corresponding pixel locations exceeding a threshold value. The print medium is printed on in the image area at an interlace level which is dependent upon the determination.

Abstract: A cartridge for an electrophotographic machine having a sump for carrying an agitator rotatably mounted in the sump for engagement with a toner; an encoded device coupled to a first end of the agitator; and a torque sensitive coupling connected to a second end of the agitator which is connectable to a drive mechanism of the machine. The encoded device includes coding representing cartridge characteristic information.

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: 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: 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: 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: Compensation for beam separation of multiple laser beams of a laser printer simultaneously scanning a photoconductor drum is automatically made. The time for the lead beam to travel a predetermined distance is ascertained and then the separation time between the lead beam and one of the remaining beams is determined. When using only one light sensor, the time for the lead beam to travel the predetermined distance is the scan time of the lead beam. When using two light sensors, the time for the lead beam to travel the predetermined distance is the time for the lead beam to travel between the two light sensors, which define the predetermined distance, in the same scan. This determination of the time for the lead beam to travel the predetermined distance and its separation time from another of the remaining beams is continuously made for all of the remaining beams even during printing.

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: A method of printing with an ink jet printer compensates for skewed printing on a print medium. An image area is defined on the print medium which has a plurality of rows of pixel locations and a plurality of columns of pixel locations. A printhead includes a plurality of vertically adjacent ink emitting orifices arranged in an array having a height. The printhead is scanned during first and second scans across the print medium in directions transverse to the advance direction. The ink is jetted onto the print medium from the ink emitting orifices during the first and second scans at selected ink dot placement locations generally corresponding to one of the columns of pixel locations. An offset is determined in a transverse direction between a bottom ink dot placement location associated with the first scan and a top ink dot placement location associated with the second scan. The array of ink emitting orifices is segmented into at least two vertically adjacent segments of ink emitting orifices.

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: Disclosed is a replaceable media guide for use with a sheet feeding mechanism. The media guide includes a support plate, an edge guide projecting substantially at right angles from the support plate, and a first sheet engaging friction pad engaged with the support plate. The guide is designed so that the first friction pad faces a friction roller of a sheet feeding mechanism when the guide is mounted on the sheet feeding mechanism. A sheet feeding apparatus is also provided in which the media guide is inserted into the sheet feeding mechanism.

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.

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: Digital halftoning is used to reduce the number of pixel levels used to represent a multiple dot plane image to a smaller number of pixel levels for display on an output device such as an ink-jet printer. Two algorithms commonly used to halftone the dots of a given dot plane are error diffusion and ordered dither. Error diffusion produces patterns of dots that are pleasing to the human visual system but is computationally complex. Ordered dither operates quickly but produces patterns of dots that are visually objectionable. A method is taught in the present invention that employs error diffusion to halftone dot planes that contain relatively dark dots that are visually apparent, and employs ordered dither to halftone dot planes that contain relatively light dots that are not noticeable. The resulting output is pleasing to the human visual system and computed quickly.

Abstract: A printing system and method is provided that compacts bitmap print data by determining, per each swath of a page to be printed, the beginning and ending points of each "area" containing pels that will actually be printed within the swath, the locations of the starting and ending slices of each of these areas, and determining "voids" containing a sufficient minimum number of consecutive blank slices within the swath. A void is identified when a number of consecutive blank slices exceeds a predetermined threshold value. The printhead of the printing system will be turned off at the beginning of the void, and then turned back on as it approaches the end of the void, which would correspond to the beginning of the next area to be printed.

Abstract: The invention is directed to a method of manufacturing a printhead in an ink jet printer for jetting an ink onto a print medium. An advance speed of the print medium in a feed direction in the ink jet printer is determined. An approximate drying time of the ink after being jetted onto the print medium from the printhead is also determined. At least two rows of ink emitting orifices are formed in the printhead, with each row of orifices extending substantially across a width of the print medium. Each row of orifices is spaced apart from an adjacent row of orifices in the feed direction a distance which is dependent upon the advance speed of the print medium and the drying time of the ink.

Abstract: A method of printing an image on a print medium with ink using an ink jet printer. A printhead has a plurality of ink emitting orifices for jetting ink onto the print medium, with the ink emitting orifices being spaced apart in the advance direction a common distance. The printhead is movable in a direction transverse to the advance direction in incremental steps, with the incremental steps having a minimum step distance. An image area has a plurality of rows and columns of pixel locations. The columns of pixel locations have an advance pixel resolution which is dependent upon the common distance. The rows of pixel locations have a transverse pixel resolution which is dependent upon the minimum step distance. A threshold matrix is defined with a plurality of rows and columns of cells, with each cell corresponding to one of the pixel locations in the image area. A threshold value is assigned to each cell within the threshold matrix.