In image forming apparatus, a control unit determines nozzles corresponding to the image to be printed, correspondingly to a position of a print sheet, and causes a recording head to eject ink from the nozzles. A correction processing unit performs a correction process corresponding to each of plural ink ejection malfunction positions in the image. If the number of the ink ejection malfunction positions detected with a predetermined ink droplet size exceeds a predetermined upperlimit value, the correction processing unit prints a test pattern using the control unit with an ink droplet size larger than the predetermined ink droplet size, determines as a preferential ink ejection malfunction position an ink ejection malfunction position that ink ejection malfunction is also detected in the test pattern on the basis of a scanned image of the test pattern, and preferentially performs the correction process for the preferential ink ejection malfunction position.

An ink printing process employs per-nozzle droplet volume measurement and processing software that plans droplet combinations to reach specific aggregate ink fills per target region, guaranteeing compliance with minimum and maximum ink fills set by specification. In various embodiments, different droplet combinations are produced through different print head/substrate scan offsets, offsets between print heads, the use of different nozzle drive waveforms, and/or other techniques. Optionally, patterns of fill variation can be introduced so as to mitigate observable line effects in a finished display device. The disclosed techniques have many other possible applications.

Methods and systems are described herein for driving droplet ejection devices with multi-level waveforms. In one embodiment, a method for driving droplet ejection devices includes applying a multi-level waveform to the droplet ejection devices. The multi-level waveform includes a first section having at least one compensating edge and a second section having at least one drive pulse. The compensating edge has a compensating effect on systematic variation in droplet velocity or droplet mass across the droplet ejection devices. In another embodiment, the compensating edge has a compensating effect on cross-talk between the droplet ejection devices.

Methods and systems are described herein for driving droplet ejection devices with multi-level waveforms. In one embodiment, a method for driving droplet ejection devices includes applying a multi-level waveform to the droplet ejection devices. The multi-level waveform includes a first section having at least one compensating edge and a second section having at least one drive pulse. The compensating edge has a compensating effect on systematic variation in droplet velocity or droplet mass across the droplet ejection devices. In another embodiment, the compensating edge has a compensating effect on cross-talk between the droplet ejection devices.

A liquid discharging head includes a discharge port that discharges a liquid, a pressure chamber that communicates with the discharge port, and an energy generating element that is disposed in the pressure chamber. In the liquid discharging head, the discharge port is provided with a plurality of projections that project towards a central portion of the discharge port from an inner peripheral edge of the discharge port, and an interval between the projections at a location where the projections are closest to each other is 5 m or less.

An imprint apparatus, comprises: a discharge unit that discharges a liquid onto a substrate; a storage unit that stores a plurality of discharge conditions for the discharge unit; and a control unit that controls the discharge unit based on a discharge condition that is stored in the storage unit, wherein the control unit selects the discharge condition from the plurality of discharge conditions in accordance with a discharge spacing for discharging the liquid.

A method for adjusting an inkjet printing apparatus, an inkjet printing method, an inkjet printing apparatus, and a system including the same. The inkjet printing apparatus includes a plurality of nozzles, and the method for adjusting the inkjet printing apparatus includes: obtaining images of liquid drops which are output respectively from the plurality of nozzles during an inkjet printing process after the liquid drops are dried; and adjusting a driving parameter of at least one nozzle of the plurality of nozzles based upon the images of the liquid drops which are output respectively from the plurality of nozzles after the liquid drops are dried, so that volumes of the liquid drops which are output respectively from the plurality of nozzles are substantially same.

A liquid discharging head includes a discharge port that discharges a liquid, a pressure chamber that communicates with the discharge port, and an energy generating element that is disposed in the pressure chamber. In the liquid discharging head, the discharge port is provided with a plurality of projections that project towards a central portion of the discharge port from an inner peripheral edge of the discharge port, and an interval between the projections at a location where the projections are closest to each other is 5 m or less.

In an example, a piezoelectric printhead assembly includes a micro-electro mechanical system (MEMS) die including a plurality of nozzles. An application-specific integrated circuit (ASIC) die is coupled to the MEMS die by a plurality of wire bonds, wherein each of the wire bonds corresponds to a respective nozzle of the plurality of nozzles. An arbitrary data generator (ADG) on the ASIC is to provide a digital data sequence, and a multiplier is to scale multiple nozzles of the plurality of nozzles.

An inkjet print head includes a droplet ejection unit having a pressure chamber; a first actuator configured for changing a volume of the pressure chamber; a second actuator configured for changing the volume of the pressure chamber; and a nozzle orifice. The inkjet print head further includes a control circuitry operatively connected to the first actuator and the second actuator. The control circuitry includes a drive circuitry for supplying a drive signal to at least one of the first and the second actuator; a sensing circuitry for receiving a sense signal from the first actuator; and a switch circuitry for switching a connection of the first actuator between a connection to the drive circuitry and a connection to the sensing circuitry.