It is disclosed an amplifier for driving a capacitive load, comprising an input terminal adapted to receive an input voltage signal, an output terminal adapted to drive the capacitive load, a linear amplification stage, switching amplification stage, a capacitor, a first switch and a measurement and control circuit. The measurement and control circuit is configured to: measure the value of the current generated at the output from the linear amplification stage and generate a driving voltage signal of the switching amplification stage; generate the first switching signal to open the first switch and generate an enabling signal to enable the operation of at least part of the switching amplification stage; generate the first switching signal to close the first switch and generate the enabling signal to disable the operation of the switching amplification stage; generate the first switching signal to open the first switch.

An image forming apparatus includes a housing heater, recording heads, a head heater, a head temperature sensor and a controller. The housing heater heats an inside of a housing. The recording heads are stored in the housing and provided for colors of ink. The head heater is provided for each of the recording heads and heats the ink stored in each of the recording heads. The head temperature sensor detects a temperature of each of the recording heads. The controller drives the housing heater until a temperature of the ink estimated based on a detection result of the head temperature sensor reaches a printing permission temperature, and controls a driving of the head heater so as to maintain the printing permission temperature after the temperature of the ink reaches the printing permission temperature.

A liquid ejecting head includes: a plurality of individual flow channels provided with nozzles; a common supply flow channel through which a liquid is supplied to the plurality of individual flow channels; a common discharge flow channel through which the liquid is discharged from the plurality of individual flow channels; and a bypass flow channel that bypasses the plurality of individual flow channels and causes the common supply flow channel and the common discharge flow channel to communicate with each other. A combined flow channel resistance of the bypass flow channel and the plurality of individual flow channels is greater than a flow channel resistance of the common supply flow channel and is greater than a flow channel resistance of the common discharge flow channel.

There is provided a liquid discharge apparatus including: a conveyer; head chips; a circulation channel; and a controller. Each head chip includes a manifold; a nozzle group, and actuators. Each head chip is configured to execute discharge drive and non-discharge vibration drive. The head chips include: an end head chip; a facing head chip facing the recording medium; and a non-facing head chip not facing the recording medium. The controller is configured to make at least one of a circulation flowing amount of a liquid in the circulation channel in the facing head chip and a frequency of the non-discharge vibration drive by an actuator included in the actuators in the facing head chip larger than those of the non-facing head chip.

A method for depositing droplets onto a medium, utilising a droplet deposition head is provided. The head used in the method includes: an array of fluid chambers separated by interspersed walls, each fluid chamber communicating with an aperture for the release of fluid droplets and each wall separating two neighbouring chambers. Each wall is actuable such that in response to a first voltage, it will deform so as to decrease the volume of one chamber and increase the volume of the other chamber, and, in response to a second voltage, it will deform so as to cause the opposite effect on the volumes of its neighbouring chambers. The method includes the steps of: receiving input data: assigning, based on such input data, all the chambers within the array as either filing chambers or non-firing chambers, so as to produce bands of one or more contiguous filing chambers separated by bands of one or more contiguous non-firing chambers; actuating the walls of certain of the chambers such that: for each non-firing chamber, either one wall is stationary while the other is moved, or the walls move with the same sense, or they remain stationary: and, for each firing chamber the walls move with opposing senses; such actuations result in each firing chamber releasing at least one droplet, the resulting droplets forming bodies of fluid disposed on a line on the medium, such bodies of fluid being separated on the line by respective gaps for each of the bands of non-firing chambers, the size of each such gap generally corresponding in size to the respective band of non-firing chambers. The actuations of the walls of said firing chambers in the actuating step are such that, if only one of the two walls of each firing chamber were actuated in such manner, no droplets would be ejected from that firing chamber. A droplet deposition apparatus, a droplet deposition head and a computer program product are also provided.

A liquid discharge apparatus includes a liquid discharger and circuitry. The liquid discharger includes a nozzle to discharge liquid. The circuitry is configured to generate and output a common drive waveform including a plurality of drive pulses for discharging the liquid; select one or more of the plurality of drive pulses from the common drive waveform and apply the one or more of the plurality of drive pulses to a pressure generating element of the liquid discharger; and adjust, with different adjustment values, application waveform shapes of at least two of the plurality of drive pulses applied to the pressure generating element.

A droplet ejection apparatus including a droplet deposition head, actuating circuitry and head controller circuitry. The droplet deposition head having an array of actuating elements and a corresponding array of nozzles. The actuating circuitry applies drive waveforms to the actuating elements causing the ejection of fluid in the form of droplets through the array of nozzles and onto deposition media, which are moved relative to the droplet deposition head. The head controller circuitry is configured to receive an input set of ejection data, generate a series of sub-sets of ejection data based on the input set, and send the series of sub-sets of ejection data to the actuating circuitry. The actuating circuitry is further configured so as to, for each sub-set of ejection data, apply drive waveforms to the actuating elements such that they repeatedly eject droplets from one or more nozzles, thus depositing successive rows of droplets. The one or more nozzles and the sizes of the droplets ejected therefrom are determined by the current sub-set of ejection data. Each of the one or more nozzles ejecting droplets with a substantially constant frequency of 1/T. The apparatus is further configured to receive deposition media speed data, which indicates the current speed of relative movement of the head with respect to the deposition media. The apparatus is further configured such that the head switches from ejecting droplets in accordance with a current sub-set of ejection data to ejecting droplets in accordance with a consecutive sub-set of ejection data in the series at a time determined in accordance with the media speed data, with the time interval between starting ejecting droplets in accordance with successive sub-sets of ejection data varying inversely with the current speed of relative movement of the droplet deposition head.

A printing apparatus prints an image by applying ink to a print surface of an inclined print medium using a print head. A control apparatus for the printing apparatus acquires information on an inclination of the print surface. Based on the information, printing is controlled according to a print condition corresponding to a magnitude of the inclination of the print surface.

A system comprises a printhead including a nozzle, a temperature sensor and a processor. The temperature sensor detects the temperature of a location of a print surface upon firing the nozzle to eject a drop of printing fluid to the location of the print surface. The processor determines whether the nozzle ejected the drop properly using the detected temperature.

A method, computer program product and system for precision inkjet printing. A control variable vector of actuation parameters associated with an inkjet waveform is determined. A printhead is then actuated to eject a grid of droplets from an inkjet onto a substrate based on the inkjet waveform. An image of the grid of droplets on the substrate is acquired. The acquired image is then processed to calculate a fitness function of the inkjet waveform that includes a function of sensed output variables associated with printing characteristics. The control variable vector is then adjusted by updating its topology based on the fitness function to obtain an optimized control variable vector associated with an optimized inkjet waveform.