Abstract: A method to eliminate ink trajectory errors when an inkjet printhead is fabricated is disclosed. In a preferred embodiment, a nozzle member containing an array of orifices is affixed to a barrier layer formed on a having heater elements formed thereon. The nozzle member is affixed to the barrier layer using heat and pressure. The back surface of the nozzle member extends beyond the outer edges of the substrate. During the heating and pressure step used to affix the nozzle member to the barrier layer, the nozzle member tends to undesirably bend over the outer edges of the barrier layer, causing the nozzles to be tilted outward. To avoid the foregoing the barrier layer is formed with one or more trenches parallel to the long edges of the barrier layer to cause the nozzle member to dip and bend over the trenches in an amount approximately equal to the bend into the ink channels on the outer edge of the substrate.

Abstract: This disclosure describes an improved ink seal between a print cartridge body and an inkjet printhead. In a preferred embodiment, a nozzle member containing an array of orifices has a substrate, having heater elements formed thereon, affixed to a back surface of the nozzle member. Each orifice in the nozzle member is associated with a single heating element formed on the substrate. The back surface of the nozzle member extends beyond the outer edges of the substrate. Ink is supplied from an ink reservoir to the orifices by a fluid channel within a barrier layer between the nozzle member and the substrate. The fluid channel in the barrier layer may receive ink fl owing around two or more outer edges of the substrate or may receive ink which flows through a hole in the center of the substrate.

Abstract: A technique for controlling print quality in an inkjet printer by delivering synchronized heating, non-printing pulses and printing pulses to the ink firing resistors during print firing operations such as during the printing of a swath. A temperature of the printhead substrate is measured and compared against a reference temperature during printing operations. If the measured temperature is below the reference temperature, then the printhead substrate is heated during the printing operations to bring the substrate up to the reference temperature. The heating is done by delivering synchronized heating non-printing pulses and printing pulses to the ink firing resistors during selected print firing periods, wherein either the heating pulses or the printing pulses, but not both, occur during a selected print firing period. The heating pulses are logically OR-ed with the printing pulses to achieve the synchronization.

Abstract: A method of operating a thermal inkjet printer having a thermal inkjet printhead that includes the steps of selecting an ink drop volume, selecting a pulse width that will cause the thermal inkjet printhead to deposit an ink drop having the selected drop volume, and operating the thermal inkjet printhead with the selected pulse width and at an operating energy that is greater than a turn-on energy of the printhead for the selected pulse width.

Abstract: Methods and apparatus generate, and use in printing, a dither matrix that incorporates a vivid-response function, that follows a generally S-shaped response curve. Printing with this pregenerated dither cell is just as fast as with a conventional cell, but printed color has a slightly exaggerated vividness, more pleasing to most users than more-accurately reproduced color. Color printed with this curve alone, however, is found unsatisfactorily dark; the invention also encompasses including in the overall response another function to lighten the colors--particularly at the low end of the brightness range. We define both functions as so-called "gamma functions", but with different arguments and exponents, and construct the S-shaped curve as two separate sections blended at a generally central point. Preferably the argument of the first (low-brightness) section is an expression that is proportional to an input color signal; the function raises this argument to a power greater than unity (ideally 1.6).

Abstract: When a thermal inkjet print cartridge operates to eject ink, three things happen at once: (1) heating by the heating resistor with flow of heat into the ink chamber; (2) cooling by heat drain toward the reservoir, print cartridge body and to ambient; and (3) cooling by carrying away of heat in the ink drops and replacement by cooler ink from the reservoir. The present invention is a method of detecting a depleted ink supply by monitoring the temperature of the printhead substrate with a temperature sensitive resistive trace on the printhead surface. When the print cartridge is warmed with warming pulses to a temperature higher than its normal operating temperature: and then firing pulses are implemented to eject ink, the temperature measured by the thermal sense resistor will decrease if the print cartridge is ejecting its normal, or nearly normal, amount of ink. If the print cartridge is ejecting less than its normal amount of ink the temperature will decrease less, stay the same, or even increase.

Abstract: A printer/copier apparatus is adapted to receive a replacement ink cartridge that is employed during the printing/copying operation. The apparatus includes a receptacle with a first connector that is coupled to a processor which controls operation of the apparatus. The cartridge includes a second connector which mates with the first connector and a serial access memory that is connected to the second connector. Data transfers are enabled both from and to the memory to enable access and modification of data stored therein that is indicative of cartridge usage, calibration, and to parameters for controlling operation of the apparatus. The invention is applicable to replaceable apparatus used with laser and ink jet printers, copiers, etc.

Abstract: A means is provided to eliminate ink trajectory errors when an inkjet printhead is fabricated as described below. In a preferred embodiment, a nozzle member containing an array of orifices is affixed to a barrier layer formed on a substrate, the substrate having heater elements formed thereon. The nozzle member is affixed to the barrier layer using heat and pressure. Each orifice in the nozzle member is associated with a single heating element formed on the substrate. The back surface of the nozzle member extends beyond the outer edges of the substrate. During the heating and pressure step used to affix the nozzle member to the barrier layer, the nozzle member undesirable bends over the outer edges of the barrier layer, causing the nozzles to be tilted outward.

Abstract: Disclosed is a method of determining imminent ink exhaustion in a thermal inkjet print cartridge based on the discovery that ink drop volume falls at a faster rate at high frequency firing rates than at low frequency firing rates as ink supply diminishes. The method includes warming the print cartridge printhead and ink to a predetermined temperature; then operating the print cartridge printhead at a first firing frequency to eject a volume of ink, said operating step including heating the ink and printhead, carrying away heat in the ejected volume of ink, and conveying a volume of cooler ink to the printhead to replace the ejected volume; and monitoring a first temperature change from the predetermined temperature.

Abstract: This system selectively enables a printer to deposit primary or black color dots at pixel locations on a sheet to produce a color image--in such a way as to increase the overall number of dots used in the image, thereby minimizing contrast between dots on the sheet and adjacent areas and so providing a better simulation of a continuous-tone image. The result is print quality often near that of error diffusion, usually better than any dither technique, but with the greater speed of a dither technique. The system includes a memory for storing a first color vector for each pixel in the image, respectively, and a processor coupled to the memory for determining a second color vector from each of the first vectors, respectively. The processor accomplishes this determination by replacing a fraction of the black color component of the first vector with primary colors.

Abstract: An improved ink flow path between an ink reservoir and ink ejection chambers in an inkjet printhead is disclosed along with a preferred printhead architecture. In the preferred embodiment, a barrier layer containing ink channels and firing chambers is located between a rectangular substrate and a nozzle member containing an array of orifices. The substrate contains two spaced apart arrays of ink ejection elements, and each orifice in the nozzle member is associated with a firing chamber and ink ejection element. The ink channels in the barrier layer have ink entrances generally running along two opposite edges of the substrate so that ink flowing around the edges of the substrate gain access to the ink channels and to the firing chambers.

Abstract: A simple and inexpensive method for halftone printing by an inkjet printer is disclosed. Improved halftone printing in an inkjet printer is provided by varying the ink drop volume of an thermal inkjet printhead by controlling the pulse width of the delivered firing pulses.

Abstract: Described is an inkjet print cartridge including an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber; said ink firing chambers arranged in a first chamber array and a second chamber array and said firing chambers spaced so as to provide 600 dots per inch printing; an ink channel connecting said reservoir with said ink firing chambers, said channel including a primary channel connected at a first end with said reservoir and at a second end to a secondary channel; a separate inlet passage for each firing chamber connecting said secondary channel with said firing chamber for allowing high frequency refill of the firing chamber; a group of said firing chambers in adjacent relationship forming a primitive in which only one firing chamber in said primitive is activated at a time; a first circuit on said substrate connected to said firing elements; and a second circuit on said cartridge connected to said first circuit, for transmitting firing

Abstract: To prevent rubbing of the printing mechanism against still wet ink on a buckled or curled sheet of an absorbent print medium after an inkjet printer has printed one swath of a high density image, printing of the next swath is delayed as a function of the maximum density of the ink drops deposited on the print medium for the printed swath(s). The required delay in printing the next swath is dependent on print mode and preferably uses a formula with empirically derived constants to allow sufficient time for the solvent in the ink to evaporate or otherwise disperse and to permit any buckling or curling of the print medium to stabilize.

Abstract: Described is an ink delivery system for an array of nozzle orifices in a print cartridge comprising an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber; an ink channel connecting said reservoir with said ink firing chambers, said channel including a primary channel connected at a first end with said reservoir and at a second end to a secondary channel; a separate inlet passage for each firing chamber connecting said secondary channel with said firing chamber for allowing high frequency refill of the firing chamber; a group of said firing chambers in adjacent relationship forming a primitive in which only one firing chamber in said primitive is activated at a time; first circuit means on said substrate connected to said firing elements; and second circuit means on said cartridge connected to said first circuit means, for transmitting firing signals to said ink firing elements at a frequency greater than 9 kHz.

Abstract: Disclosed is an inkjet print cartridge including an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber along a top surface of said substrate and having a first outer edge along a periphery of substrate; the first outer edge being in close proximity to the ink firing chambers. The ink firing chambers are arranged in a first chamber array and a second chamber array and with the firing chambers spaced so as to provide 600 dots per inch printing. An ink channel connects the reservoir with the ink firing chambers, the channel including a primary channel connected at a first end with the reservoir and at a second end to a secondary channel; the primary channel allowing ink to flow from the ink reservoir, around the first outer edge of the substrate to the secondary channel along the top surface of the substrate so as to be proximate to the ink firing chambers.

Abstract: Disclosed is an inkjet print cartridge having an ink reservoir; a substrate having a plurality of individual ink firing chambers with an ink firing element in each chamber along a top surface of the substrate and having a first outer edge along a periphery of substrate; the first outer edge being in close proximity to the ink firing chambers. The ink firing chambers are arranged in a first chamber array and a second chamber array and with the firing chambers spaced so as to provide 600 dots per inch printing. An ink channel connects the reservoir with the ink firing chambers, the channel including a primary channel connected at a first end with the reservoir and at a second end to a secondary channel; the primary channel allowing ink to flow from the ink reservoir, around the first outer edge of the substrate to the secondary channel along the top surface of the substrate so as to be proximate to the ink firing chambers.

Abstract: Provided is a system and method for selectively enabling a printer to deposit on a sheet cyan, magenta, yellow and black (C,M,Y and K) primary or black color dots at each of the plurality of pixel locations to produce a color image. The system comprises a memory for storing C, M, Y and K values for each pixel in the color image and a processor for controlling selective deposition of the C, M, Y and K colors. The system includes a memory for holding a color vector for each pixel, respectively in the color image; a memory for storing parameters of a dither cell; and a processor coupled to the memory for comparing the dither cell with each color vector, to select a color component to print at the corresponding pixel location based on the comparison. The system provides a halftoning technique that produces print quality near error diffusion quality with the speed of a dither by dithering on a color vector.

Abstract: Color inkjet printers commonly employ a plurality of print cartridges, usually either two or four, mounted in the printer carriage to produce a full spectrum of colors. In order to optimize print quality, it is desirable to minimize the distance between a thermal inkjet printhead and the media that is being printed on. In a multiple printhead printer only one printhead can be the closest one to the media due to the various mechanical tolerances of the printer. Since black text print quality is more sensitive to printhead-to-media distance than is color graphics quality, the overall print quality of both black text and color graphics is optimized by assuring that the black print cartridge is closest to the media.

Abstract: A method of assembling a collapsible ink reservoir for a liquid ink printer cartridge comprising the steps of attaching a first sidewall to a frame member along a sealable junction to form an open assembly; assembling a pressure regulator; inserting the pressure regulator of said assembly step into the open assembly of said attaching step; and affixing a second sidewall to the open assembly of said attaching step to form an enclosed assembly.