Abstract: An interconnection arrangement for an inkjet printing system having multiple power pads, each of which provides power for driving a large number of printhead ink ejection elements. The ink ejection elements of a print cartridge are organized into groups, with power provided to each group by one of the power pads. The firing pulse width of each group is independently set to compensate for the parasitic electrical resistances in the power path of each ink ejection group in the print cartridge so as to eject ink drops of uniform volume required for high quality printed output. In order to transmit the relatively high current levels required to fire a large number of ink ejection elements from a single group at the same time, the interconnection scheme provides multiple bump-and-dimple interconnections with the printer for each power and ground pad on the print cartridge.

Abstract: A thermal ink jet print head with numerous firing elements on a die, and a temperature sensor on the die with a sensor voltage output proportional to a sensed temperature. A digital to analog converter has a digital input and an output voltage proportional to the value of a digital word received by the digital input, and a comparator has a first input connected to the sensor voltage output and a second input connected to the converter voltage output. The comparator generates an equivalency signal when the converter output voltage exceeds the sensor output voltage. The print head may have a temperature controller that compares the digital word to a preselected temperature threshold value to determine if the temperature is within a selected range, and which changes the temperature of the die in response to a determination that the temperature is outside of the selected range.

Abstract: A method of operating a thermal ink jet printer with a removable print head having a plurality of ink firing resistors, the operation including calibrating the printer by determining a nominal input voltage above a threshold necessary for simultaneous operation of a plurality of the resistors. Then, during printing, detecting the input voltage on the print head at an input node connected to the resistors and generating a firing pulse having a duration based on the detected input voltage at the node. Thus, a detected input voltage higher than the nominal voltage is compensated for by a shortened firing pulse. The method may be achieved in a removable ink jet print head having a connector with many electrical inputs connectable to a printer, and a voltage input node connected to the connector. The print head has numerous firing resistors connected to the input node.

Abstract: A thermal ink jet print head with numerous firing elements on a die, and a temperature sensor on the die with a sensor voltage output proportional to a sensed temperature. A digital to analog converter has a digital input and an output voltage proportional to the value of a digital word received by the digital input, and a comparator has a first input connected to the sensor voltage output and a second input connected to the converter voltage output. The comparator generates an equivalency signal when the converter output voltage exceeds the sensor output voltage. The print head may have a temperature controller that compares the digital word to a preselected temperature threshold value to determine if the temperature is within a selected range, and which changes the temperature of the die in response to a determination that the temperature is outside of the selected range.

Abstract: For each printhead nozzle, nozzle circuitry includes a warming transistor, drive transistor and heating resistor. To maintain a threshold temperature at the printhead, a warming pulse is sent from the warming transistor to the heating resistor of one or more nozzles when the temperature falls below a prescribed temperature. To fire a nozzle a firing pulse is output from the drive transistor to the heating resistor. The warming transistor is laid out as a segmented portion of the drive transistor layout area. No layout penalty is incurred by including the warming transistor for each nozzle. The source of a warming transistor is coupled in common to the source of a drive transistor. The drain of the warming transistor is coupled in common to the drain of the drive transistor. The gates are separate. The gates receive respective warming or firing control signals. The drains are coupled to the heating resistor.

Abstract: An interconnect structure and method for forming the same for electrically connecting a main contact point with a plurality of use points. The interconnect structure includes a uniform high resistance layer. A low resistance layer is formed on the uniform high resistance layer. The low resistance layer defines first and second conductors extending between a main contact point and corresponding first and second use points. The first conductor has a corresponding conductor width that is, at least in part, based on a resistance between the first and second conductors.

Abstract: For each printhead nozzle, nozzle circuitry includes a warming transistor, drive transistor and heating resistor. To maintain a threshold temperature at the printhead, a warming pulse is sent from the warming transistor to the heating resistor of one or more nozzles when the temperature falls below a prescribed temperature. To fire a nozzle a firing pulse is output from the drive transistor to the heating resistor. The warming transistor is laid out as a segmented portion of the drive transistor layout area. No layout penalty is incurred by including the warming transistor for each nozzle. The source of a warming transistor is coupled in common to the source of a drive transistor. The drain of the warming transistor is coupled in common to the drain of the drive transistor. The gates are separate. The gates receive respective warming or firing control signals. The drains are coupled to the heating resistor.

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 drive circuit for an EL device defines a power cycle and performs energy recovery. During a charging phase of the power cycle, a first energy storage device (i.e., inductor) sequentially releases small energy portions from a power source into the EL device. The energy portions incrementally accumulate to create a high energy potential across the EL device. During a discharging phase of the power cycle, a second energy storage device (i.e., inductor) sequentially accepts small energy portions from the EL device to decrementally discharge the EL device. A switching scheme is implemented to pump the energy storage devices to sequentially release or accept the small energy portions. Energy recovery is performed by capturing some of the EL device discharge energy and introducing it back to the EL device during a subsequent charging phase.