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: A fluid ejection device may include a substrate, a first group of fluid drivers on the substrate, a second group of fluid drivers on the substrate, a memory element storing a predetermined offset value and electronics to receive an address of one of the fluid drivers of the first group for actuation control. The electronics may select one of the fluid drivers of the second group for actuation control based on the address and the stored offset value.

Abstract: In some examples, a circuit for a fluid ejection device includes an energy delivery device and a circuit layer. The circuit layer includes first and second activation devices connected to the energy delivery device, the first and second activation devices to activate the energy delivery device, first drive logic coupled to the first activation device, and second drive logic coupled to the second activation device. An interconnect layer couples a same address selection signal to the first drive logic and the second drive logic.

Abstract: In some examples, a print head comprises a plurality of nozzles comprising respective heaters on the print head, each heater of the heaters to be driven by a respective firing pulse to form a bubble in a corresponding nozzle. The print head further comprises a first time repository on the print head to store a first time instant, and a second time repository on the print head to store a second time instant, and a plurality of detect circuits provided onto the print head and coupled to corresponding nozzles of the plurality of nozzles, wherein each respective detect circuit of the plurality of detect circuits is to detect a change in respective impedances for a respective nozzle at the first time instant and the second time instant.

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: According to an example, a printing system may include a drop ejecting element and a fluid circulating element corresponding to the drop ejecting element. The printing system may also include a logic device that is to receive a data stream addressed to the drop ejecting element, determine whether the data stream indicates that the drop ejecting element is to be energized, and in response to a determination that the data stream does not indicate that the drop ejecting element is to be energized, energize the fluid circulating element.

Abstract: A printhead including an address line for communicating a set of addresses and a number of primitives, each primitive including a plurality of controllable activation devices coupled to the address line, each switch corresponding to at least one address of the set of addresses, each address corresponding to one of a number of primitive functions. A buffer receives a series of data packets, each data packet including address bits representative of one address of the set of addresses. Address logic receives the address bits from the buffer, wherein for each data packet the address logic encodes the address represented by the address bits onto the address line, and wherein the at least one switch corresponding to the address activates the primitive function corresponding to address.

Abstract: Printheads and techniques for manufacturing printheads are disclosed. An example method includes forming drive circuit components in a circuit layer. The method also includes forming a fluidic device that causes fluid to be ejected from a nozzle. The method also includes forming an interconnect layer that couples the drive circuit components.

Abstract: According to an example, a printing system may include a drop ejecting element and a fluid circulating element corresponding to the drop ejecting element. The printing system may also include a logic device that is to receive a data stream addressed to the drop ejecting element, determine whether the data stream indicates that the drop ejecting element is to be energized, and in response to a determination that the data stream does not indicate that the drop ejecting element is to be energized, energize the fluid circulating element.

Abstract: In an example, a print head comprises a nozzle to be activated by a delayed fire pulse that is delayed from an initial fire pulse, a sensor to measure an impedance of the nozzle, and a detector to determine a first time instant following the delayed fire pulse for registering a first impedance measurement by the sensor.

Abstract: First electronics may determine a count of bubble jet resistors to be fired by a fire pulse group. A fire pulse generator may generate a fire pulse train for bubble jet resistors, the fire pulse train comprising a precursor pulse and a firing pulse separated by a dead time. Second electronics may adjust a width of the fire pulse for the bubble jet resistors of the fire pulse group by maintaining a first edge of the fire pulse relative to the precursor pulse and adjusting a second edge of the fire pulse relative to the precursor pulse based upon the determined count for the fire pulse group.

Abstract: In some examples, a fluid die includes a fluid nozzle, a first latch, a second latch, and a timing circuit comprising a counter and a comparator. The timing circuit is to trigger the first latch, at a first predetermined time instant from an edge of a firing pulse, to store a first test result obtained based on a voltage measured across the fluid nozzle, and trigger the second latch, at a second predetermined time instant from the edge of the firing pulse, to store a second test result obtained based on a voltage measured across the fluid nozzle.

Abstract: In some examples, a print head includes a plurality of nozzles, a test result register to store a drive bubble detect (DBD) test result for a first nozzle of the plurality of nozzles, and a result-ready register to store a status indication set to a predetermined value provided responsive to storing of the DBD test result in the test result register, where the test result register and the result-ready register are accessible by a control unit outside the print head to evaluate a nozzle condition based on the DBD test result in the test result register.

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 fluid ejection device includes a plurality of analog devices, and a storage element storing an authentication value based on electrical characteristics of a subset of the plurality of analog devices.

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: A method of operating a printing device during a power loss event includes, with a power loss detection device, detecting an power loss to a number of high voltage devices. The method further includes, with a voltage regulator coupled to printhead fire control circuitry, maintaining a power loss protection supply voltage (VDD_plp) to the printhead fire control circuitry.

Abstract: Fluid ejection devices with multiple activation modes are disclosed. An example printhead assembly includes a fluid ejection nozzle, a first resistor fluidically coupled to the fluid ejection nozzle, and a second resistor fluidically coupled to the fluid ejection nozzle. The example printhead also includes an addressing circuit to receive a nozzle address and an activation mode to activate the fluid ejection nozzle. The activation mode determines which of the first resistor and the second resistor are to be energized.

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: A printhead including an address line for communicating a set of addresses and a number of primitives, each primitive including a plurality of controllable activation devices coupled to the address line, each switch corresponding to at least one address of the set of addresses, each address corresponding to one of a number of primitive functions. A buffer receives a series of data packets, each data packet including address bits representative of one address of the set of addresses. Address logic receives the address bits PULSE POWER GROUND from the buffer, wherein for each data packet the address logic encodes the address represented by the address bits onto the address line, and wherein the at least one switch corresponding to the address activates the primitive function corresponding to address.