Xaar Technology Limited

Ian Anthony Hurst

Stephen Mark Jeapes

Neil Christopher Bird

Andrew L Van Brocklin

Mujahid-ul Islam

Mario Massucci

Anirban Lahiri

Anthony Saugey

James Edward David Marchant

Stephen Jeapes

Mujahid-Ul Islam

A drive circuit () for driving actuators of a printhead () from a common drive waveform has a switching circuit () for coupling the common drive waveform to an actuator (), and a timing circuit () to control the switching circuit to form a drive pulse from the common drive waveform. The drive pulse is trimmed by controlling a duration (TTRIM) of a step at an intermediate level (VHOLD) in the drive pulse. This can improve the trade-off between available range of trimming and thermal efficiency because the voltage drop across the switching circuit can be reduced, compared to trimming only the height. Decoupling during a flat portion of the common drive waveform can enable the timing of the decoupling to be more relaxed compared to decoupling during a slope. Such relaxing can enable costs, complexity and thermal loading to be reduced.

Actuator drive circuit with trim control of pulse shape

There is provided a droplet deposition apparatus comprising: control circuitry configured to generate a common drive waveform; storage to store data, wherein the storage comprises a buffer to store scheduled image data relating to one or more pixels; a droplet deposition head having one or more actuator elements configured to be driven in response to drive pulses derived from the common drive waveform; and wherein the common drive waveform comprises a plurality of pixel periods comprising a firing phase and a non-firing phase, each firing phase comprising a firing pulse and each non-firing phase comprising a non-firing pulse, wherein the characteristics of each non-firing pulse are defined in response to the data in storage, and wherein, the firing pulse of a first pixel period is applied as a drive pulse to an actuator element based on the scheduled image data relating to a first pixel, and wherein the non-firing pulse of the first pixel period is applied as a drive pulse to the actuator element based on past image data and/or the stored scheduled image data.

Droplet-deposition apparatus and methods of driving thereof

A printhead circuit for providing pulses for driving two or more actuating elements, the circuit comprising a cold switch drive circuit, for driving an actuating element for a first phase of a first pulse, the cold switch drive circuit having a cold drive switch for selectively coupling a drive waveform to the actuating element during the first phase according to a print signal; and a hot switch drive circuit, for driving the actuating element for a second phase of the first pulse, wherein the hot switch drive circuit is configured to drive the actuating element during the second phase according to an actuating element compensation indication signal.

Printhead circuit

A driver circuit for driving actuating elements for printing, has a switch for coupling a common drive signal to provide element drive pulses to drive each actuating element according to a print signal. A timing control circuit controls the switch during sloped transitions of the common drive signal, to trim an amplitude of the actuating element drive pulses according to a common offset configurable for at least two of the actuating elements in common, and according to an element specific offset, configurable for each of the actuating elements. The offsets can be dynamic or static, and some parts of the timing can be implemented in analog form. This enables more types of errors to be compensated, and can enable the element specific offset to be implemented with simpler circuitry with less heat dissipation or less space or needing less precision and thus less cost.

Actuating element driver circuit with trim control

A printhead for a printer has actuating elements for ejecting fluid, and a drive circuit for selectively applying a drive waveform having several slopes, to an actuating element, according to a print signal. A resulting printhead has a lesser sensitivity to changes of slew rate in one slope of the drive waveform than a sensitivity to change in another. The drive circuit has a variable resistance circuit, and a control circuit to control the variable resistance circuit to adjust a slew rate of the slope of lesser sensitivity according to a trim signal. By making the adjustment less sensitive, the trim signal and trim control can have more relaxed tolerances, thus can employ simpler, cheaper circuitry.

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Wilburton, United Kingdom

Ian Anthony Hurst