Xaar Technology Limited

Mujahid-ul Islam

Stephen Mark Jeapes

Neil Christopher Bird

Anirban Lahiri

Ian Anthony Hurst

Mario Massucci

Anthony Saugey

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 disclosed a controller for controlling two or more groups of nozzles in an array, the controller configured to: encode data blocks into a data stream, wherein each data block denotes how a respective group of nozzles is to be controlled for a droplet period; encode fire codes into the data stream, wherein each fire code is a reserved code that denotes when a respective group of nozzles is to be controlled in accordance with the data block for the droplet period; and wherein the data block precedes the fire code for the respective group of nozzles in the data stream and wherein the fire codes are generated independently of the data blocks.

Droplet deposition apparatus and controller therefor

A test circuit to determine the capacitance of an actuator element in an actuator element array, wherein the test circuit comprises: a controller; a source to generate test inputs; measurement circuitry to measure one or more test values on a test path between the test circuit and the actuator element; wherein the controller is configured to, for a test period: control a first switch associated with the actuator element to connect the actuator element to the test path; control the source to generate a first test input; and determine a total capacitance of the actuator element from a first test value generated in response to the first test input; and determine the capacitance of the actuator element (C) from the total capacitance (C+C).

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Griton, United Kingdom

Mujahid-ul Islam