Printheads and methods of operation. In one embodiment, a printhead includes a plurality of jetting channels comprising first jetting channels configured to jet a first print fluid and second jetting channels configured to jet a second print fluid, and a driver circuit communicatively coupled to actuators of the jetting channels. The driver circuit receives a drive waveform comprising first jetting pulses provisioned for the first print fluid and second jetting pulses provisioned for the second print fluid, and gating signals comprising a first active gating signal designated for jetting the first print fluid and a second active gating signal designated for jetting the second print fluid. The driver circuit selectively applies the first jetting pulses to actuators of the first jetting channels based on the first active gating signal, and selectively applies the second jetting pulses to actuators of the second jetting channels based on the second active gating signal.

In some examples, a fluid dispensing device includes a reservoir containing a fluid, fluidic actuators, and an interface to receive a data packet comprising information to control activation of the fluidic actuators, the data packet comprising a random number generated by a random number generator.

According to one embodiment, an inkjet head includes a pressure chamber for ink, a nozzle plate including a nozzle connected to the pressure chamber, an actuator to change a volume of the pressure chamber, and a drive circuit that drives the actuator. The drive circuit drives the actuator according to a drive waveform including an expansion waveform, a first weak contraction waveform, a contraction waveform, and a second weak contraction waveform.

In one example in accordance with the present disclosure, a fluidic die is described. The fluidic die includes a number of zones. Each zone includes a number of sets of fluidic devices. Each fluidic device includes a fluid chamber and a fluid actuator disposed in the chamber. Each fluidic device also includes a sensor to sense a characteristic of the zone and an adjustment device. The adjustment device 1) delays a firing signal received from a previous zone as it passes by each set of fluidic devices and 2) adjusts the firing signal as it enters the zone based on a sensed characteristic.

In the print data for a nozzle of a printer, white dots are replaced by pre-ejection pulses. One or more repetitions of the pre-ejection pulses may be inserted into the print data, depending on the actual print speed of the printer, to determine print speed-dependent print data with which the nozzle is activated to print a print image with high print quality.

An image forming apparatus includes a transportation belt, a print engine, and an ejection timing control unit. The transportation belt transports a print sheet. The print engine ejects ink onto the print sheet. The ejection timing control unit adjusts an ink ejection timing of the print engine. The transportation belt includes a flushing opening part. The print engine repeatedly performs ink flushing to the flushing opening part at predetermined timings. Further the ejection timing control unit derives an adjustment amount for the ink ejection timing of the print engine on the basis of: a number of the ink ejection timings in a period from a previous flushing time to a current flushing time, a distance from the flushing opening part for the flushing at the previous flushing time to the flushing opening part for the flushing at the current flushing time, and a print resolution.

A print component includes an array of fluidic actuation structures including a first column of fluidic actuating structures addressable by a set of actuation addresses, each fluidic actuating structure having a different one of the actuation addresses and having a fluidic architecture type, and a second column of fluidic actuating structures addressable by the set of actuation addresses. Each fluidic actuating structure of the second column has a different one of the actuation addresses and has a same fluidic architecture type as the fluidic actuating structure of the first column having the same address. An address bus communicates the set of addresses to the array of fluidic actuating structures, and a fire signal line communicates a plurality of fire pulse signal types to the array of fluidic actuating structures, the fire pulse signal type depending on the actuation address on the address bus.

A liquid discharge head is provided, which includes a nozzle plate which is formed with nozzles, and a channel member which is formed with pressure chambers and connecting channels for connecting the pressure chambers and the nozzles. The connecting channel includes a plurality of portions which have mutually different channel cross-sectional areas. The plurality of portions includes a first portion which is adjacent to the pressure chamber, and a second portion which is adjacent to the first portion, the first portion being interposed between the pressure chamber and the second portion. The first portion has the smallest channel cross-sectional area of those of the plurality of portions. S1≤0.3×S0 and S1≤0.7×S2 are fulfilled (S0: channel cross-sectional are of the pressure chamber, S1: channel cross-sectional area of the first portion, S2: channel cross-sectional area of the second portion).

A wide array printhead module includes a plurality of printhead die, each of the printhead die includes a number of nozzles. The nozzles form a number of primitives. A nozzle firing heater is coupled to each of the nozzles. An application specific integrated circuit (ASIC) controls a number of activation pluses that activate the nozzle firing heaters for each of the nozzles associated with the primitives. The activation pulses are delayed between each of the primitives via internal delays and external delays to reduce peak power demands of the printhead die. The ASIC determines the internal delays within each printhead die.

In a method for operating an inkjet print head for generating a droplet of a liquid, the inkjet print head comprises a number of ejection units, each ejection unit comprising a piezo-electric actuator having a signal electrode, a common electrode and a piezo-electric layer interposed between the signal electrode and the common electrode. The method comprises providing a non-jetting pulse signal on a common electrode, wherein the non-jetting pulse signal is adapted to generate a pressure wave in the liquid in the corresponding ejection unit without expelling a droplet of the liquid. The method further comprises providing a jetting pulse signal on a signal electrode, wherein the jetting pulse signal is adapted to generate a pressure wave in the liquid in the corresponding ejection unit such that a droplet of the liquid is expelled.

Further, an inkjet print head assembly comprising an inkjet print head and a control circuitry is provided. The inkjet print head assembly is configured for performing the above method.