Abstract: 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 (CACT) from the total capacitance (CPAR+CACT).

Abstract: A circuit for driving first and second groups of actuating elements for ejection of droplets from a printhead, the circuit comprising: a drive circuit configured to provide a drive waveform to first electrodes of the first and second groups; and a voltage offset circuit configured to provide a voltage offset to the second electrodes of the first or second groups to bias the second electrodes of the first and second groups relative to each other.

Abstract: An inkjet printhead comprising a printhead die, the printhead die comprising: a plurality of actuators; a plurality of electrical connections in electrical communication with respective first electrodes of the plurality of actuators for providing drive signals thereto; a first electrical bus arranged in common electrical communication with second electrodes of a first group of the actuators for providing first signals thereto; and a second electrical bus arranged in common electrical communication with second electrodes of a second group of the actuators for providing second signals thereto.

Abstract: An actuator component for a droplet deposition head that includes: a plurality of fluid chambers arranged side-by-side in an array, with certain of the fluid chambers being firing chambers, each of which is provided with at least one piezoelectric actuating element for causing droplet ejection from a nozzle for that firing chamber; and a plurality of non-actuable walls, each of which is formed of piezoelectric material and bounds at least one of the firing chambers.

Abstract: There is disclosed a piezoelectric thin film element comprising a first electrode, a second electrode and one or more piezoelectric thin films there between characterised in that the thin film element has at least two of: an electrode arrangement in which electrodes are arranged with the one or more piezoelectric thin films so that an electric field applied to a piezoelectric thin film or a portion of a piezoelectric thin film adjacent to the first electrode is lower than an electric field applied to a piezoelectric thin film or a portion of a piezoelectric thin film further from the first electrode when the piezoelectric thin film element actuated; a piezoelectric thin film adjacent to the first electrode in which a layer of the piezoelectric thin film near to the first electrode has a piezoelectric displacement constant which is lower than that of a layer of the piezoelectric thin film further from the first electrode; and a piezoelectric thin film adjacent to the first electrode in which a layer of the

Abstract: A printhead circuit or driving at least two actuating elements has a trim generating circuit for generating a trim signal using a comparator coupled to receive and compare feedback indicative of a present level of a drive voltage, with a configurable reference voltage value. The trim being based on a drive voltage feedback can give a more direct indication of actuating element output than given by timing references. Hence the trim can be more accurate, can be simpler, without accurate digital timing references, and thus costs can be reduced. It can be combined with a cold switch arrangement.

Abstract: 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.

Abstract: A droplet deposition apparatus, such as an inkjet printhead, that includes an integrally-formed manifold component and one or more actuator components; these actuator components provide an first array of fluid chambers, each of which has a piezoelectric actuator element and a nozzle, with this piezoelectric actuator element being able to cause the release in a deposition direction of fluid droplets through the nozzle in response to electrical signals; the first array of fluid chambers extends in an array direction from a first longitudinal end to a second, opposite longitudinal end, this array direction being perpendicular to the deposition direction; in addition, the manifold component is elongate in the array direction and includes a first and second manifold chambers, with these manifold chambers extending side-by-side in the array direction and the first manifold chamber being fluidically connected to the second manifold chamber via each of the fluid chambers in the first array; the cross-sectional area o

Abstract: A piezoelectric thin film element having a first electrode, a second electrode and a piezoelectric thin film between the electrodes, wherein the thin film comprises a laminate having two or more piezoelectric thin film layers and wherein a first thin film layer is doped by one or more dopants and a second film layer is doped by one or more dopants and wherein at least one dopant of the second thin film layer is different from the dopant or dopants of the first thin film layer.

Abstract: A printhead circuit or driving at least two actuating elements has a trim generating circuit for generating a trim signal using a comparator coupled to receive and compare feedback indicative of a present level of a drive voltage, with a configurable reference voltage value. The trim being based on a drive voltage feedback can give a more direct indication of actuating element output than given by timing references. Hence the trim can be more accurate, can be simpler, without accurate digital timing references, and thus costs can be reduced. It can be combined with a cold switch arrangement.

Abstract: 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.

Abstract: A droplet deposition apparatus, such as an inkjet printhead, that includes an integrally-formed manifold component and one or more actuator components; these actuator components provide an first array of fluid chambers, each of which has a piezoelectric actuator element and a nozzle, with this piezoelectric actuator element being able to cause the release in a deposition direction of fluid droplets through the nozzle in response to electrical signals; the first array of fluid chambers extends in an array direction from a first longitudinal end to a second, opposite longitudinal end, this array direction being perpendicular to the deposition direction; in addition, the manifold component is elongate in the array direction and includes a first and second manifold chambers, with these manifold chambers extending side-by-side in the array direction and the first manifold chamber being fluidically connected to the second manifold chamber via each of the fluid chambers in the first array; the cross-sectional area o

Abstract: Droplet deposition apparatus including at least one droplet ejection unit having a plurality of fluid channels disposed side by side in a row, an actuator, and a plurality of nozzles, said actuator being actuable to eject a droplet of fluid from a fluid channel through a respective nozzle, a support member for said at least one droplet ejection unit, a first conduit extending along said row and to one side of both said support member and said at least one droplet ejection unit for conveying droplet fluid to each of the fluid channels of said at least one droplet ejection unit; and a second conduit extending along said row and to the other side of both said support member and said at least one droplet ejection unit for receiving droplet fluid from each of the fluid channels of said at least one droplet ejection unit.

Abstract: A printhead provides actuation pulses for driving actuating elements from a common drive waveform via respective switching circuits, the waveform having a pre-charge ramp followed by a steeper slope. A start voltage of a leading edge of the actuation pulse is set by opening the switching circuit to decouple the common drive waveform from its actuating element part way along the pre-charge ramp. After the pre-charge ramp the actuating element is coupled again to the common drive waveform, so that the voltage across the actuating element follows the steeper slope to form the leading edge. Adjusting the timing of the decoupling adjusts the start voltage, enables trimming relative to other actuating elements. The gentle slope of the pre-charge ramp enables the precision of timing of switching to be more relaxed, so that trigger circuitry for controlling the switching circuit can be simpler, smaller, cheaper and thermally more efficient.

Abstract: A printhead assembly comprising the printhead and filters intended for use with the printhead is passivated by passing a gaseous coating such as Parylene through the assembly. In this way dirt particles created during manufacture of the printhead are encapsulated and thus prevented from blocking the nozzles. The printhead assembly is also prevented from interacting physically or chemically with ink flowing through the printhead.

Abstract: A mounting arrangement for mounting a printer component to a support, using a foil including a number of mounting apertures, into which pins are inserted to provide alignment. The engagement of the pins in the aperture causes local deformation of the foil, the resulting forces acting to align the pins to an accuracy which can be greater than that to which the foil is manufactured.

Abstract: Droplet deposition apparatus including at least one droplet ejection unit having a plurality of fluid channels disposed side by side in a row, an actuator, and a plurality of nozzles, said actuator being actuable to eject a droplet of fluid from a fluid channel through a respective nozzle, a support member for said at least one droplet ejection unit, a first conduit extending along said row and to one side of both said support member and said at least one droplet ejection unit for conveying droplet fluid to each of the fluid channels of said at least one droplet ejection unit; and a second conduit extending along said row and to the other side of both said support member and said at least one droplet ejection unit for receiving droplet fluid from each of the fluid channels of said at least one droplet ejection unit.

Abstract: Depositing droplets onto a substrate using an array of channels, acting as fluid chambers, separated by actuable walls. In response to a first voltage, each wall deforms to decrease the volume of one channel and increase the volume of the other channel, and, in response to a second voltage, the wall deforms so as to cause the opposite effect on the volumes of the neighboring channels. Receiving input data; assigning, based on the input data, all channels within the array as firing or non-firing to produce groups of one or more contiguous firing channels separated by groups of one or more contiguous non-firing channels; actuating walls of certain channels resulting in each of the firing channels releasing at least one droplet of fluid, the resulting droplets forming dots disposed on a straight line on a substrate, separated on the line by gaps corresponding to the non-firing channels.

Abstract: A method for controlling the printing of overlapping swathes, the swathes extending perpendicular to a succession of print lines; for each print line a transition is defined between one swathe and the next, with the location of the transition in the print line varying between print lines, for example varying pseudo-randomly or as a curve extending in the swathe direction.

Abstract: A method for depositing droplets onto a substrate employs an apparatus, such as an inkjet printhead, the apparatus having: an array of channels, acting as fluid chambers, separated by interspersed walls, with each channel communicating with an aperture or nozzle for the release of droplets of a fluid contained within the channel, such as ink. Each of the walls separates two neighboring channels and is actuable such that, in response to a first voltage, it will deform so as to decrease the volume of one channel and increase the volume of the other channel, and, in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of the neighboring channels. The method includes the steps of: receiving input data, such as an array of image data pixels; selecting pairs of adjacent channels based on the input data; assigning the selected pairs of adjacent channels as firing channels and the remaining channels as non-firing channels.