Abstract: A method of calibrating an electrophotographic machine having an image-bearing surface includes estimating a reflectivity of the image-bearing surface based upon an amount of usage of the electrophotographic machine. At least one electrophotographic condition is adjusted dependent upon the estimating step.

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 calibrating an electrophotographic machine having an image bearing surface includes depositing a toner patch on the image-bearing surface. The toner patch has a nominal coverage that varies substantially continuously from end to end. Light is emitted onto a selected one of the areas of the toner patch. An amount of light that is reflected off of the selected one area of the toner patch is measured. The emitting and measuring steps are repeated for each of a plurality of different areas of the toner patch. At least one electrophotographic condition is adjusted. The adjusting is dependent upon the measuring steps.

Abstract: An electrophotographic machine has at least two printing modes, with each printing mode having a respective printing density. A method of calibrating the electrophotographic machine includes depositing at least one toner patch on an image-bearing surface. The depositing is performed in a first of the printing modes. Light is emitted onto the at least one toner patch. An amount of light that is reflected off of the at least one toner patch is measured. At least one first electrophotographic condition for the first printing mode is adjusted dependent upon the measuring step. At least one second electrophotographic condition is adjusted for a second of the printing modes. The adjusting of the at least one second electrophotographic condition is dependent upon the measuring step.

Abstract: An electrophotographic image forming apparatus includes a photoconductive drum and a transfer roll-positioned adjacent to and defining a nip with the drum. An image substrate travels through the nip in an advance direction. A toner cartridge assembly is positioned in association with the drum and above the image substrate. A pre-transfer erase assembly having a light emitting outlet is positioned between the toner cartridge assembly and the image substrate. The light emitting outlet is directed toward the drum.

Abstract: A refillable cartridge for inkjet printing devices having an ink cartridge carrier is characterized in that it is filled with an ink supply and tested prior to shipment, is open to ambient pressure during shipment and storage, requires no handling of the ink supply line during installation on, or removal from, a cartridge carrier, and permits simultaneous fluid and electrical connections to the cartridge as it is installed. Partitions divide the interior of the cartridge into a free ink reservoir, a foam-filled ink reservoir and an air buffer region. An ink passage permits ink flow in either direction between the ink reservoir and the foam-filled ink reservoir. A tab circuit is secured to one side wall of the cartridge and this wall is provided with an opening through which a hollow ink supply needle, mounted on the cartridge carrier, may extend so as to supply replenishment ink to the free ink reservoir during printing.

Abstract: The invention relates to an ink level sensing apparatus including an ink cartridge having an ink chamber containing ink and having at least one substantially transparent side panel adjacent the ink chamber. A fluorescent material is disposed in the ink chamber, the fluorescent material being substantially insoluble in the ink and having a specific gravity which is sufficiently lower than the ink to provide an interface between the ink and the fluorescent material. A relatively narrow band light source for emitting light at a first wavelength along a light path through the substantially transparent side panel of the ink cartridge is provided for exciting the fluorescent material. A photosensor for receiving light emitted from a fluorescent material at a second wavelength when the excited fluorescent material crosses the light path is provided, wherein the first and second wavelengths are substantially different.

Abstract: Various methods and apparatus are disclosed for facilitating the loading, transportation, and modulation of toner particles on a print head, as well as the transfer of toner particles onto a print medium. These methods and apparatus relate to the optimization of various elements on the print head to improve the speed and control of toner particles on the print head, as well as to the alteration of the electric field in the vicinity of the end of the print head.

Abstract: A system for intermittently refilling the cartridge reservoir in an ink jet printer from an off-board ink supply tests the ink flow path prior to initiating a refill operation. Air at a pressure greater than the ink feed pressure is applied to the ink flow path to check the integrity of the system. After venting the system to the atmosphere, a slow leak check is made by closing the system, pressurizing it at the feed pressure, turning off the pressure source and, after a short interval, checking the pressure to see if the feed pressure is being maintained. If the integrity check or the slow leak test should fail, the refill operation is aborted and an indicator is set to alert an operator that intervention is required. During the interval the system is being raised from atmospheric to feed pressure, the air displacement is measured and saved as an indication of whether the amount of ink in the off-board supply exceeds a given level.

Abstract: A color ink jet printing device has an off-board ink reservoir for each color being printed. Each reservoir comprises at least two separately replaceable cartridges from which ink is supplied under positive pressure to refill replaceable printhead cartridges. A visual indicator is provided for each off-board cartridge to indicate when the cartridge is empty and this indicator is turned on if the ink supply in the cartridge is exhausted during a refill operation. Printing is not stopped until all off-board cartridges holding one color of ink are empty. At this time the empty cartridges that held any color ink, are replaced. After each operator intervention to replace empty cartridges, the volume of each color ink will be (N−1)/N of maximum reservoir capacity where N is an integer greater than one and represents the number of cartridges in the reservoir.

Abstract: An ink jet print cartridge is provided for use in an ink jet printer. The cartridge comprises a printhead including a heater chip. The printhead is adapted to generate ink droplets in response to the heater chip receiving energy pulses from a printer energy supply circuit. A peltier effect cooling cell is associated with the heater chip for cooling the heater chip. The cooling cell receives current from the printer energy supply circuit as a function of energy flow to the heater chip.

Abstract: Various methods and apparatus are disclosed for facilitating the loading, transportation, and modulation of toner particles on a print head, as well as the transfer of toner particles onto a print medium. These methods and apparatus relate to the optimization of various elements on the print head to improve the speed and control of toner particles on the print head, as well as to the alteration of the electric field in the vicinity of the end of the print head.

Abstract: Various methods and apparatus are disclosed for facilitating the loading, transportation, and modulation of toner particles on a print head, as well as the transfer of toner particles onto a print medium. These methods and apparatus relate to the optimization of various elements on the print head to improve the speed and control of toner particles on the print head, as well as to the alteration of the electric field in the vicinity of the end of the print head, and to the use of a scanning print head.

Abstract: Various methods and apparatus are disclosed for facilitating the loading, transportation, and modulation of toner particles on a print head, as well as the transfer of toner particles onto a print medium. These methods and apparatus relate to the optimization of various elements on the print head to improve the speed and control of toner particles on the print head, as well as to the alteration of the electric field in the vicinity of the end of the print head.

Abstract: A refillable cartridge for inkjet printing devices having an ink supply off-board the cartridge carrier is characterized in that it is filled with an ink supply prior to shipment and the refill opening through which replenishment ink is supplied during printing is left open during shipment and storage. The interior of the cartridge is partitioned into a free ink reservoir, a foam-filled ink reservoir and an air buffer region. The foam-filled ink reservoir is filled with a foam material saturated with ink prior to shipment. A portion of the foam material extends into the air buffer region and is left dry. As long as the refill opening is not closed, ambient pressure is applied to the ink supply in the cartridge via the refill opening and the air buffer region. An ink passage permits ink flow in either direction between the free ink reservoir and the foam-filled ink reservoir. Either reservoir may be connected to ink capillaries in a conventional heater chip.

Abstract: Various methods and apparatus are disclosed for facilitating the loading, transportation, and modulation of toner particles on a print head, as well as the transfer of toner particles onto a print medium. These methods and apparatus relate to the optimization of various elements on the print head to improve the speed and control of toner particles on the print head, as well as to the alteration of the electric field in the vicinity of the end of the print head, and the transfer of toner particles vertically from the print head.

Abstract: A laser printer includes at least three laser beams for simultaneously scanning a rotatable recording medium. The laser beams have their centers spaced uniform or non-uniform distances from each other. The centers of the laser beams are spaced predetermined distances from each other so that the print resolution may be 300, 400, 600, or 1,200 dpi depending upon the laser beams selected for use with at least two laser beams always being selected.

Abstract: Standard, unfixed electrophotographic images are transferred from a photoconductor drum (5) to paper (7) at a nip location with a transfer roller (3). The paper remains in contact with the transfer roller until it is positioned under a ink jet printhead (9), where a second image, typically color highlights, is printed. This configuration requires no additional registration of the two images. The ink jet printhead may be charged to repel stray toner which might clog its nozzles. The transfer member may be a belt or may be large enough to permit movement of the paper at the higher speeds of electrophotographic at the transfer station and at the lower speeds of ink jet printing when the paper is at the ink jet printing station.