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.

A liquid jetting apparatus includes: a first head chip having first nozzles arranged in a nozzle arrangement direction; a second head chip having second nozzles arranged in the nozzle arrangement direction, and being arranged to overlap at least partially with the first head chip in an orthogonal direction orthogonal to the nozzle arrangement direction; a controller configured to control the first head chip and the second head chip to jet liquid from the first nozzles and the second nozzles; and power sources having different voltages, respectively. Each of the first nozzles and the second nozzles is driven by voltage supplied from one of the power sources, and the first head chip has a first overlapping portion and the second head chip has a second overlapping portion overlapping with the first overlapping portion in the orthogonal direction.

A liquid jetting apparatus includes: a head including nozzles and driving elements arranged to correspond to the nozzles; a power source connected to the driving elements; and a control circuit connected to the power source. The control circuit determines whether an output voltage value of the power source is changed from a first voltage value to a second voltage value. When the control circuit has determined that the output voltage value is changed from the first voltage value to the second voltage value, the control circuit calculates an absolute value of a difference between the first voltage value and the second voltage value and compares the absolute value of the difference and a threshold value. When the absolute value of the difference is equal to or more than the threshold value, the control circuit determines a calculation voltage value smaller than the absolute value of the difference.

A method of ink jet printing, wherein liquid ink is supplied to a plurality of nozzles via a common ink supply passage, and actuators associated with the nozzles are controlled to cause ink droplets to be expelled from the nozzles in accordance with image information to be printed, characterized by the steps of: detecting a situation where a number of the nozzles which are connected to the common ink supply passage and are presently active but stop printing within a given time interval is larger than a given maximum number; if that situation is detected, activating at least one actuator associated with one of the nozzles that stop printing with sub-threshold agitation pulses which cause an agitation of a meniscus in the nozzle without a droplet being expelled.

A control system includes a control circuit. The control circuit is to be connected to a head unit including first driving elements and second driving elements. Based on an input print data, the control circuit applies a first signal to the first driving element and applies a second signal to the second driving elements. The control circuit changes the first signal to a third signal in a first time and changes the second signal to a fourth signal in a second time. Based on an input print data, the control circuit applies the third signal to the first driving element and applies the fourth signal to the second driving elements.

A liquid jetting apparatus includes: a head including nozzles and driving elements arranged to correspond to the nozzles; a power source connected to the driving elements; and a control circuit connected to the power source. The control circuit determines whether an output voltage value of the power source is changed from a first voltage value to a second voltage value. When the control circuit has determined that the output voltage value is changed from the first voltage value to the second voltage value, the control circuit calculates an absolute value of a difference between the first voltage value and the second voltage value and compares the absolute value of the difference and a threshold value. When the absolute value of the difference is equal to or more than the threshold value, the control circuit determines a calculation voltage value smaller than the absolute value of the difference.

A recording apparatus includes a head and a controller. The controller discriminates first and second regions on a recording medium based on received image data, sets a boundary region that includes a boundary of the first and second regions, sets a first discharge speed for a discharge speed of droplets from the head to be landed to a first main region included in the first region, sets a second discharge speed slower than the first discharge speed for a discharge speed of droplets from the head to be landed to a second main region included in the second region, and sets a discharge speed between the first discharge speed and the second discharge speed for a discharge speed of droplets form the head to be landed to the boundary region.

The head has a passage member having a nozzle and a pressurizing chamber which is communicated with the nozzle and is positioned on the side opposite to the side where the nozzle is opened, a piezoelectric actuator substrate which is superimposed on the passage member so as to cover the pressurizing chamber, and a flexible printed circuit which faces the piezoelectric actuator substrate from the opposite side to the passage member. The piezoelectric actuator substrate has a piezoelectric body which is exposed on the flexible printed circuit side. The piezoelectric body has a via hole opened toward the flexible printed circuit and has a projection portion at the edge part of the via hole which projects to the flexible printed circuit side.

A drive signal output circuit that outputs a drive signal for driving a piezoelectric element includes an integrated circuit that outputs a first control signal, a first switching element operated by the first control signal, and a wiring board on which the integrated circuit and the first switching element are provided, wherein the first switching element includes a first transistor chip, a first terminal, a second terminal, and a third terminal all of which are electrically coupled to the first transistor chip, and a first mold member covering the first transistor chip, wherein a conduction state between the second terminal and the third terminal is controlled according to the first control signal input to the first terminal, and wherein the first terminal, the second terminal, and the third terminal are provided only at positions overlapping with the first mold member along a direction normal to the wiring board.

A head unit includes heads arranged in a body. Each head includes a nozzle row arranged along a first direction. The heads are arranged along a second direction intersecting with the first direction. Two or more heads that include a nozzle row corresponding to a first color, are provided in each of a first region and a second region. A color corresponding to the nozzle row at an nth position from a first side is the same as a color corresponding to the nozzle row at an nth position from a second side, n being a positive integer, the first side being one side of the body in the second direction and the second side being another side of the body in the second direction.