An ink drop measurement pad is for measuring volumes and positions of inkjet drops that are sprayed and dropped in a constant volume from nozzles of a head of an inkjet device. The ink drop measurement pad includes a pattern part including a plurality of groove portions arranged at pitch intervals corresponding to those of a plurality of head nozzles and wall portions formed between the groove portions. The groove portions are uniformly formed so as to have the same cross-section throughout an entire longitudinal direction thereof.

A droplet of fluid having a predetermined drop weight is ejected from a microfluidic channel. Electrical signals are received from a sensor in the microfluidic channel, wherein the electrical signals vary in response to the ejection of the droplet of fluid. The electrical signals of the sensor are calibrated to a rate of flow of fluid through the microfluidic channel based on a number of droplets ejected and the predetermined drop weight of each droplet.

A droplet discharge apparatus may include a droplet discharge unit configured to discharge droplets of a target substance stored in a tank at intervals through an opening of a nozzle connected to the tank, a speed sensor configured to measure the speed of a droplet discharged from the droplet discharge unit, and a calculation unit configured to calculate the volume of the target substance consumed per unit time, based on cross-sectional area of the opening of the nozzle and the speed of the droplet.

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.

A driving waveform determining method with which a waveform of a driving pulse applied to a driving element provided in a liquid ejecting head that ejects a liquid is determined includes: a first step of measuring, by performing a simulation, ejection characteristics of the liquid from the liquid ejecting head when a waveform candidate is used for the driving pulse; a second step of measuring, by performing an actual measurement, the ejection characteristics of the liquid from the liquid ejecting head when the waveform candidate is used for the driving pulse; and a third step of determining the waveform of the driving pulse in accordance with a measurement result obtained in the first step and a measurement result obtained in the second step.

A printing apparatus includes a printer with printing elements that print dots and a controller that acquires input image data. The controller acquires a pre-correction printing density that is based on test pattern data, which includes a uniform array of pixels, and printing characteristics of printing positions of the dots printed by the plurality of printing elements. The controller calculates a target density by averaging the pre-correction printing density and offsets the target density so that the target density is equal to or greater than the pre-correction printing density. The controller calculates a correction gain of the plurality of printing elements on the basis of the ratio of the target density to the pre-correction printing density and controls the printer on the basis of the correction gain and the input image data.

There is disclosed a housing including a plurality of compartments for housing a plurality of LEDs or photo detectors. Each compartment has a number of control pads projecting inwardly and a number of protrusions. The control pads are configured to provide a contact surface for the LEDs or photo detectors to control the alignment and position of each of the plurality of LEDs or photodiodes within each of the plurality of compartments. Each of the protrusions urges each of the plurality of LEDs or photodiodes against the respective control pads to control the alignment of the LEDs or photodiodes in the housing. A detector array including a casing, an LED housing and a photodiode housing is also disclosed.

An image forming apparatus 101 capable of performing printing with a high image quality, and a control method of the image forming apparatus 101 are provided. For this purpose, a threshold value Dt is preliminarily set that allows printing without occurrence of blur, for each of preliminarily set monitoring areas A. In the case where a print duty for each of the monitoring areas A has exceeded the threshold value Dt, an ejection frequency of ink and conveying speed of a print medium are reduced in association therebetween.

A three-dimensional object is made of curable ink and includes a color layer serving as an outer surface. The color layer includes color ink and clear ink filling a space between dots of the color ink. A rate of the color ink to the clear ink decreases toward an outer side. With this configuration, the clear ink ensures diffusion of light beams reflected by dots of the color ink in a portion close to the outer side of the color layer. This ensures improved granular texture on the surface of the three-dimensional object.