Abstract: A low ink sensing system is combined with an ink cartridge detection system to enable a more efficient ink jet printer. An ink container which supplies ink to an associated printhead is modified by the incorporation of two light directing elements, in the preferred embodiment, a curvilinear prism-like structure and a curvilinear roof mirror, into a transparent wall of the container housing. The cartridge, comprising the ink container and associated printhead, is mounted on a scan carriage. Periodically, the carriage is conveyed to a sensing station comprising a pair of light sources and a commonly used photosensor. A first light source is energized and a beam of light is directed to a location where the curvilinear roof mirror would be positioned if the cartridge is present. If the cartridge is absent, lack of a reflected return signal is sensed, indicating a cartridge has not been inserted. Print operation is halted until a cartridge is inserted.

Abstract: An ink jet printer that includes a printhead for ejecting ink droplets, an ink container for supplying ink to the printhead, and an ink level sensor for measuring the level of ink in the ink container, includes an ink level sensor activator. The ink level sensor activator causes the ink level sensor to measure the level of ink in the ink container after the printhead has ejected a predetermined quantity of ink. The ink level sensor activator records the quantity of ink ejected by the printhead onto the print medium by measuring to the number of droplets of ink ejected, and/or by determining the number of pixels in an image to be printed for which ink is to be ejected. If the quantity of ink ejected has a predetermined threshold, the ink level sensor measures the quantity of ink in the ink container.

Abstract: A printer determines the characteristics of the ink of the replaceble ink cartridge by set of ink cartridges. Each ink cartridge is formed of a housing and includes marks on the exterior surface of the housing. The marks on the cartridge housing are arranged so that the marks on the several ink cartridges collectively form a pattern of marks. The printer electronically scans the pattern of marks, and automatically produces an indication in accordance with the pattern of marks to identify the brand and/or type of ink contained in the set of cartridges, the ink capacity of the cartridges, as well as to verify that an appropriate combination of cartridges has been installed. Printer performance characteristics, such as expected print yield, can be determined based on the indication produced by scanning the pattern of marks.

Abstract: An ink jet printhead scrubbing and priming method and apparatus are provided. The apparatus of the method includes a capping member for capping a nozzle face of an ink jet printhead. The capping member has a bottom wall and side walls defining a capping recess and a priming path into the capping recess. A nozzle face of an ink jet printhead being capped, the bottom wall and side walls of the capping member together define an enclosed gap within the capping recess that contains air. The apparatus of the method then includes pressure applying devices for alternatingly applying positive and negative pressure within the enclosed gap and to nozzles in the nozzle face of the ink jet printhead being capped. The positive and negative pressures effectively agitate and scrub the nozzles in the nozzle face of the ink jet printhead being capped, thereby facilitating easy and effective subsequent priming of the nozzles in the nozzle face of the ink jet printhead being capped.

Abstract: To print an image having a 600 dpi resolution along the horizontal axis with an ink jet printer that has a 300 dpi resolution, the method raster scans selected pixels from a selected pixel pattern. The image receiving member is then advanced a selected distance. Remaining pixels from the selected pixel image pattern are then raster scanned onto the image receiving member to visibly reproduce the image at a defined resolution.

Abstract: A sheet inverter and stacking apparatus has at least one sheet inverter wheel having at least one arcuate sheet retaining slot into which a sheet may be inserted. The wheel is incrementally rotated from a sheet load position to a sheet unload position and a sheet is driven in the process direction into the slot when the inverter wheel is in the load position. The sheet is removed from the slot, stacked in a stacking tray and its leading edge registered. The sheet retaining slot provides minimal resistance to sheet movement in the slot upon insertion in the slot in the process direction and provides high resistance to sheet movement in the slot in a sideways direction transverse to the process direction.