Abstract: The present subject matter relates to evaluating nozzle condition of a plurality of nozzles. In one example, drive bubble detect (DBD) test results for a set of nozzles from among the plurality of nozzles are stored by a print head in a test result register, where the test result register is provided onto the print head. Further, status bits of a result-ready register provided in the print head are set to a predetermined value by the print head responsive to storing of the DBD test results in the test result register. Further, based on the setting, the DBD test results are obtained by a control unit, from the test result register, for evaluating the nozzle condition.

Abstract: A printhead assembly includes ink ejection devices having nozzles and arranged into primitive groups, and processing electronics in communication with the ink ejection devices. The processing electronics including logic to receive data packets for controlling the ink ejection devices. Each data packet includes primitive firing data and fire signal selection data. The processing electronics also include logic to select, for each data packet, a fire signal for application to the primitive groups from among selectable fire signals switchable among the primitive groups based on the fire signal selection data in each respective packet. The processing electronics also include logic to generate the selected fire signals, and to apply the selected fire signals to the ink ejection devices based on the primitive firing data for each data packet.

Abstract: A printhead assembly includes ink ejection devices having nozzles, and processing electronics in communication with the ink ejection devices. The processing electronics implement logic to receive nozzle data for controlling the ink ejection devices, receive error detection data associated with the nozzle data, detect errors associated with the nozzle data using the error detection data, and generate fault data for the detected errors.

Abstract: Examples of an apparatus and method are disclosed herein. In an example of the method, the performance of an ejection device that dispenses a composition is measured, information representative of the measured performance of the ejection device is generated, and the information representative of the measured performance of the ejection device is recorded so that the information is visually perceptible.

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 fluid ejection device includes a plurality of analog devices, and a storage element storing an authentication value including a plurality of bits, a first bit of the plurality of bits based on measured electrical characteristics of a first subset of the analog devices, and a second bit of the plurality of bits based on measured electrical characteristics of a second subset of the analog devices, the second subset different from the first subset.

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: An example device in accordance with an aspect of the present disclosure includes modules to communicate an input signal to an ink sample to obtain an ink signal, compare the ink signal to a reference value, and identify an indicator of nozzle chamber operation corresponding to the ink signal. A module may be contained on an inkjet printhead die, such that the device may generate the input signal on the inkjet print head die.

Abstract: An example device in accordance with an aspect of the present disclosure includes modules to generate an input signal, apply the input signal to an ink sample to obtain an ink signal, compare the ink signal to a reference value, and identify whether the ink signal is consistent with an ink signature. A module may be contained on an inkjet printhead die.

Abstract: In an example, a method of managing a nozzle condition test on a printhead includes instructing a printhead to perform impedance measurements on a plurality of nozzles in a first set of nozzles. The method also includes retrieving from the printhead, an impedance measurement result corresponding with each nozzle, where each impedance measurement result indicates a nozzle condition of its corresponding nozzle.

Abstract: In an example, a method for determining an issue in an inkjet nozzle includes providing an initial fire pulse for firing a nozzle, and receiving the initial fire pulse as a delayed fire pulse at a primitive of the nozzle. The method includes firing the nozzle with the delayed fire pulse, and determining a first time instant following the delayed fire pulse for taking a first impedance measurement across the nozzle.

Abstract: The present subject matter relates to evaluating nozzle condition of a plurality of nozzles. In one example, drive bubble detect (DBD) test results for a set of nozzles from among the plurality of nozzles are stored by a print head in a test result register, where the test result register is provided onto the print head. Further, status bits of a result-ready register provided in the print head are set to a predetermined value by the print head responsive to storing of the DBD test results in the test result register. Further, based on the setting, the DBD test results are obtained by a control unit, from the test result register, for evaluating the nozzle condition.

Abstract: The present subject matter relates to evaluating print head nozzle condition of a plurality of nozzle columns. Each of the plurality of nozzle columns comprises a set of nozzles. A plurality of drive bubble detect modules are activated, by a timing circuit coupled to each of the plurality of nozzle columns upon occurrence of at least a first predetermined time instant and a second predetermined time instant. For each of the plurality of nozzle columns, test results for a nozzle of the nozzle column are registered by the corresponding drive bubble detect module. Test results obtained based on impedances measured across a nozzle associated with the nozzle column corresponding to a drive bubble detect module are registered by the drive bubble detect module at the first predetermined time instant and the second predetermined time instant. The print head nozzle condition of the nozzle is evaluated based on the test results.

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: Systems and methods for evaluating the condition of a print nozzle are described. In one example, impedances across the print nozzle are measured. Subsequently, first test result and second test result are determined and registered at a first predetermined time instant and at a second predetermined time instant, respectively. The first test result and the second test result are obtained based on the measured impedances. Based on the first test result and the second test result, the condition of the print nozzle, is determined.

Abstract: In one example, a device for driving a nozzle of a fluid-jet printing device includes a circuit to, for each pixel time of a plurality of pixel times select a waveform from a plurality of waveforms based on more than one of waveform time delay, waveform pulse width and waveform shape, and apply the selected waveform to the nozzle to drive the nozzle to eject fluid for a current pixel time.

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: 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 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.