Abstract: A print head has a jet stack, a jet stack heating and temperature measuring element thermally connected to the jet stack, the jet stack heating and temperature measuring element including: a first, etched copper layer having heat spreading characteristics and including a resistive heat source electrically connected in series to a voltage source and a switch; an electrically insulative on a back side of the first copper layer; and a second, etched copper layer on a side of the electrically insulative layer opposite the first copper layer, the second copper layer having a temperature sensing element to sense a temperature of the print head without a thermistor, the temperature sensing element connected in series with a voltage source and a transistor. A print head may use a thermistor but the heat spreading layer eliminates the need for a heat sink to attach to the print head.

Abstract: A method of correcting print banding in a printer, including initiating the banding correction process, generating prints with various levels of banding based on different levels of voltages applied to the array of jets, receiving an input from the user selecting the preferred print, and adjusting voltage levels applied to jets corresponding to the preferred print.

Abstract: An inkjet printhead including an inkjet configured to eject drops of ink in response to receiving an electrical signal, a memory configured to store image data, and a processor operatively coupled to the inkjet and the memory. The processor receives the image data and determines a period of latency of the inkjet printhead. When the period of latency is within a predetermined timeframe, the processor increases a voltage of the electrical signal to a second voltage for an initial number of drops to eject the drops of ink in a pattern of printed ink drops with reference to at least a portion of the image data and reduce the voltage of the electrical signal after the initial number of drops to eject drops of ink in a pattern of printed ink drops with reference to a remaining portion of the image data, and generates the electrical signal.

Abstract: An inkjet printhead including an inkjet configured to eject drops of ink in response to receiving an electrical signal, a memory configured to store image data, and a processor operatively coupled to the inkjet and the memory. The processor receives the image data and determines a period of latency of the inkjet printhead. When the period of latency is within a predetermined timeframe, the processor increases a voltage of the electrical signal to a second voltage for an initial number of drops to eject the drops of ink in a pattern of printed ink drops with reference to at least a portion of the image data and reduce the voltage of the electrical signal after the initial number of drops to eject drops of ink in a pattern of printed ink drops with reference to a remaining portion of the image data, and generates the electrical signal.

Abstract: A method for recovering missing inkjets in a printhead including determining an inkjet in the printhead is not ejecting ink, purging degassed ink into the printhead, adjusting a pressure in the printhead so that ink drools out of an aperture of each nozzle of the printhead, repeatedly applying a non-firing waveform at a frequency for a predetermined amount of time to the printhead while the ink drools out of the aperture of each nozzle of the printhead, and after the predetermined amount of time, adjusting the pressure in the printhead to a normal printhead pressure.

Abstract: A print head has a jet stack, a jet stack heating and temperature measuring element thermally connected to the jet stack, the jet stack heating and temperature measuring element including: a first, etched copper layer having heat spreading characteristics and including a resistive heat source electrically connected in series to a voltage source and a switch; an electrically insulative on a back side of the first copper layer; and a second, etched copper layer on a side of the electrically insulative layer opposite the first copper layer, the second copper layer having a temperature sensing element to sense a temperature of the print head without a thermistor, the temperature sensing element connected in series with a voltage source and a transistor. A print head may use a thermistor but the heat spreading layer eliminates the need for a heat sink to attach to the print head.

Abstract: Print head jet stack heating and temperature measurement systems and methods are disclosed that both heat the jet stack and determine a temperature of the jet stack. The heating and temperature determination are performed by a flex circuit that includes multiple layers. One of the layers heats the jet stack and another one of the layers provides data that determines the temperature of the jet stack. The heating layer and the temperature sensing layer are separated by an insulative material in the flex circuit. The temperature of the jet stack can be sent to a print head controller that then determines whether to increase or decrease the temperature of the jet stack.

Abstract: A method of filling a print head includes drawing a vapor into an empty print head to displace any air in the print head and filling the print head with ink. A method of filling a print head includes connecting a print head to a vacuum pump using a first valve, to a liquid supply using a second valve, and to an ink supply using a third valve, opening the first and second valves, applying vacuum to the print head and liquid supply using the vacuum pump, causing the liquid to generate a vapor that moves into the print head, closing the first valve and the second valve, and opening the third valve to move ink into the print head.

Abstract: A method for operating an inkjet printer includes identifying a pattern of ink drops ejected from an inkjet with reference to image data for a printed image, identifying a waveform component for an electrical signal operating the inkjet to eject an ink drop in the pattern of ink drops with reference to at least a portion of the image data, and generating the electrical signal with the identified waveform component to eject the ink drop in the pattern of ink drops at a first velocity onto a first location of an image receiving surface.

Abstract: The disclosed print head has a two-chamber main reservoir that decouples wasted ink and purge volume in print heads. The two-chamber structure of the print head allows for varying flow of ink through the print head's internal manifolds without varying the wasted ink out of the jet stack. The main reservoir of the print head includes a recirculation chamber and an incoming ink chamber. A vacuum is applied to a vent in the recirculation chamber and a pressure can also be applied to a vent in the incoming ink chamber to cause bubbles in the jet stack to move into the recirculation chamber and be removed through the recirculation chamber vent.

Abstract: Print head jet stack heating and temperature measurement systems and methods are disclosed that both heat the jet stack and determine a temperature of the jet stack. The heating and temperature determination are performed by a flex circuit that includes multiple layers. One of the layers heats the jet stack and another one of the layers provides data that determines the temperature of the jet stack. The heating layer and the temperature sensing layer are separated by an insulative material in the flex circuit. The temperature of the jet stack can be sent to a print head controller that then determines whether to increase or decrease the temperature of the jet stack.

Abstract: The disclosed print head has a two-chamber main reservoir that decouples wasted ink and purge volume in print heads. The two-chamber structure of the print head allows for varying flow of ink through the print head's internal manifolds without varying the wasted ink out of the jet stack. The main reservoir of the print head includes a recirculation chamber and an incoming ink chamber. A vacuum is applied to a vent in the recirculation chamber and a pressure can also be applied to a vent in the incoming ink chamber to cause bubbles in the jet stack to move into the recirculation chamber and be removed through the recirculation chamber vent.

Abstract: A method for operating an inkjet printer includes identifying a pattern of ink drops ejected from an inkjet with reference to image data for a printed image, identifying a waveform component for an electrical signal operating the inkjet to eject an ink drop in the pattern of ink drops with reference to at least a portion of the image data, and generating the electrical signal with the identified waveform component to eject the ink drop in the pattern of ink drops at a first velocity onto a first location of an image receiving surface.

Abstract: A drop emitting apparatus may include a drop generator having a piezoelectric element and configured to receive a drop firing waveform having a drop firing voltage pulse during a drop ejection period. A poling waveform may be applied to the drop generator during a poling period that occurs before the drop ejection period, the poling waveform having a poling voltage pulse that has a longer duration than that of the drop firing voltage pulse.

Abstract: A resonator module for a combustion turbine power plant, where the combustion turbine power plant defines a flow path. The resonator module includes a first member, an a second member. The first member has a size substantially smaller than the diameter of said flow path and a plurality of openings therethrough. The openings are in fluid communication with the flow path. The second member has a size generally equal to said first member. The second member is in a generally spaced relation to the first member and encloses a volume of gas between the first and second members.

Abstract: A method and system for combusting a liquid fuel stream in a diffusion flame combustor by spraying the liquid fuel stream into a steam flow to produce a fuel/steam flow with atomized liquid fuel therein. The fuel/steam flow is further mixed before being combusted in the diffusion flame combustor to produce at least a first portion of an emission stream therefrom.

Abstract: An apparatus and method for establishing a stable pilot flame at a wide range of operating conditions, having a main fuel tube, an outer tube concentrically enclosing the main fuel tube, a swirler located downstream from the outer tube, an ignitor, and several fuel manifold tubes connected to the main fuel tube, are disclosed. The fuel manifold tubes direct a portion of the pilot gas fuel stream radially outward from the remainder of the pilot fuel. The axial momentum of the radially displaced fuel stream is greater than the average axial momentum of the remainder of the pilot gas streams. This relationship between the axial momenta of the gas steams promotes flame recirculation and stabilizes the pilot flame over a wide range of operating conditions.