Abstract: A print head die includes a storage element. The print head die includes a plurality of analog devices. The storage element is to store an authentication value. The authentication value is generated based on comparisons of the measured electrical characteristics of at least some of the analog devices.

Abstract: Measuring an inkjet nozzle may include taking at least one impedance measurement after the firing command is sent to detect the presence of a drive bubble and taking another impedance measurement to detect a collapse of the drive bubble.

Abstract: A method for determining an issue in an inkjet nozzle with impedance measurements, includes taking a first impedance measurement to detect a drive bubble with an impedance sensor; and taking a second impedance measurement to detect said drive bubble with said impedance sensor after said first impedance measurement.

Abstract: Methods to program a floating gate memory array include, in response to a request to program a second bit of the floating gate memory array, at a first time, outputting a programming voltage to cause a first node voltage at a first source of a first transistor corresponding to a first bit, wherein the first node voltage is greater than a second node voltage at a second source of a second transistor corresponding to the second bit. The method further includes at a second time, increasing the programming voltage of the floating gate memory array to program the second bit of the floating gate memory array.

Abstract: A method for determining an issue in an inkjet nozzle with impedance measurements, includes taking a first impedance measurement to detect a drive bubble with an impedance sensor; and taking a second impedance measurement to detect said drive bubble with said impedance sensor after said first impedance measurement.

Abstract: A printhead system to reduce peak energy usage may include a printhead including a plurality of primitives including nozzles. A printhead control module may control the printhead to increase printed pixel resolution and to reduce peak pixel fill density for print media. The printhead control module may further control the printhead such that all the nozzles with a same address generally disposed in a column do not fire at the same time.

Abstract: A method for determining an issue in an inkjet nozzle with impedance measurements, includes taking a first impedance measurement to detect a drive bubble with an impedance sensor, and taking a second impedance measurement to detect said drive bubble with said impedance sensor after said first impedance measurement.

Abstract: A printhead system to reduce peak energy usage may include a printhead including a plurality of primitives including nozzles. A printhead control module may control the printhead to increase printed pixel resolution and to reduce peak pixel fill density for print media. The printhead control module may further control the printhead such that all the nozzles with a same address generally disposed in a column do not fire at the same time.

Abstract: A heater controller to maintain a uniform temperature of a printhead is provided herein. The heater controller monitors the temperature of the printhead and controls the heating of the printhead. The heater controller enables at least two of a plurality of warming groups based on warming power requirements of the printhead. The heater controller alternates activation of the at least two of the plurality of warming groups by rotating each of the at least two of the plurality of warming groups between an on mode and an off mode to uniformly distribute heating power to the printhead.

Abstract: A method for determining an issue with an inkjet nozzle using an impedance difference includes taking a first impedance measurement with a sensor to detect a drive bubble in an ink chamber after a drive bubble formation mechanism is activated; and subtracting the first impedance measurement from a reference.

Abstract: Crack detection circuits for printheads are described. In an example, a crack detection circuit for at least one printhead, includes: crack detectors formed on the at least one printhead; switches selectively coupling the crack detectors on each printhead to a communication bus; and a configuration circuit on each printhead coupled to control inputs of the respective switches, each configuration circuit responsive to a crack detection configuration input to control the respective switches.

Abstract: Measuring an inkjet nozzle may nozzle may include taking at least one impedance measurement after the firing command is sent to detect the presence of a drive bubble and taking another impedance measurement to detect a collapse of the drive bubble.

Abstract: A printhead apparatus, an inkjet printer system, and a method of built-in test employ a test flag transmitted through a data channel of a printhead. The apparatus includes a plurality of printheads, a data register at each printhead, and a status channel. Each printhead has a unidirectional data channel (UDC) to provide data to the printhead. The data register detects proper reception of a test flag received by the printhead through the UDC. The status channel reports printhead status information including whether or not proper reception of the test flag was detected by the data register. The system includes the apparatus and a controller to generate the test flag and receive the printhead status information. The method includes sending a test flag, and verifying proper reception thereof.

Abstract: A method for calibrating a program that detects a condition of an inkjet nozzle includes receiving measurement information from a sensor positioned to detect a drive bubble in an ink chamber of an inkjet nozzle; and modifying a program that determines a condition of said inkjet nozzle.

Abstract: A controller is for driving a nozzle of a fluid-jet printing device. The controller can select a waveform from a number of waveforms based at least on values for the nozzle. The controller can scale the waveform based on the values for the nozzle. The waveform drives the nozzle to cause the nozzle to eject fluid therefrom.

Abstract: A method and apparatus test a printed circuit assembly and a print head array with a low-power application to a printed circuit assembly having a power storage component disconnected from a power rail of the printed circuit assembly and test the printed circuit assembly and the print head array with a high-power application to the printed circuit assembly with the printed circuit assembly receiving electrical power from the power storage component.

Abstract: A heater controller to maintain a uniform temperature of a printhead is provided herein. The heater controller monitors the temperature of the printhead and controls the heating of the printhead. The heater controller enables at least two of a plurality of warming groups based on warming power requirements of the printhead. The heater controller alternates activation of the at least two of the plurality of warming groups by rotating each of the at least two of the plurality of warming groups between an on mode and an off mode to uniformily distribute heating power to the printhead.

Abstract: A printhead apparatus, an inkjet printer system, and a method of built-in test employ a test flag transmitted through a data channel of a printhead. The apparatus includes a plurality of printheads, a data register at each printhead, and a status channel. Each printhead has a unidirectional data channel (UDC) to provide data to the printhead. The data register detects proper reception of a test flag received by the printhead through the UDC. The status channel reports printhead status information including whether or not proper reception of the test flag was detected by the data register. The system includes the apparatus and a controller to generate the test flag and receive the printhead status information. The method includes sending a test flag, and verifying proper reception thereof.

Abstract: A method for calibrating a program that detects a condition of an inkjet nozzle includes receiving measurement information from a sensor positioned to detect a drive bubble in an ink chamber of an inkjet nozzle; and modifying a program that determines a condition of said inkjet nozzle.

Abstract: A method for determining an issue with an inkjet nozzle using an impedance difference includes taking a first impedance measurement with a sensor to detect a drive bubble in an ink chamber after a drive bubble formation mechanism is activated; and subtracting the first impedance measurement from a reference.