The invention discloses an inking system for a rotary printing machine, like a flexographic or rotogravure press. The inking system uses the nip area between two cylinders of the machine as the sole source for inking the printing cylinder. This results in an inking system with very little ink, thereby gaining in reaction time and ink waste.

An apparatus and methods of decorating exterior surfaces of metallic containers are provided. More specifically, the present disclosure provides a novel metering roller for an inking assembly of a decorator. An adjustment mechanism is operable to move the metering roller to a first ink transfer position during a decoration run. In the first ink transfer position, the metering roller receives ink from an ink roller without contacting the ink roller. In one embodiment, during the production run, the metering roller is in contact with and transfers ink to a transfer roller. When the decoration run stops, the adjustment mechanism can move the metering roller to a second dwell position such that the metering roller does not receive ink from the ink roller.

Examples of the preferred embodiments use an ink quantity metric (e.g., lightness L*, darkness, image density, line width) of printed content to determine thickness of fountain solution applied by a fountain solution applicator on an imaging member surface and/or determine image forming device real-time image forming modifications for subsequent printings. For example, in real-time during the printing of a print job, a sensor (e.g., spectrometer) may measure the ink quantity metric of the current printing on print substrate. Based on this measurement of printed content output from the image forming device, the image forming device may adjust image forming (e.g., fountain solution deposition flow rate) to reach or maintain a preferred fountain solution thickness on the imaging member surface for subsequent (e.g., next) printings of the print job.

Examples of the preferred embodiments use printed content (e.g., halftones, difference in grayscale or darkness) to determine thickness of fountain solution applied by a fountain solution applicator on an imaging member surface and/or determine image forming device real-time image forming modifications for subsequent printings. For example, in real-time during the printing of a print job, a sensor may measure halftones or grayscale differences between printed content and non-printed content of a current printing on print substrate. Based on this measurement of printed content output from the image forming device, the image forming device may adjust image forming (e.g., fountain solution deposition flow rate, imaging member rotation speed) to reach or maintain a preferred fountain solution thickness on the imaging member surface for subsequent (e.g., next) printings of the print job.

This document discloses a system to dispense a precise and continuous amount of ink for a large printing press. The dispensing system can be judiciously combined into a more elaborate dispensing system that uses two chambers with ink having a different density to dispense ink with a precise, adjustable and stable ink density. The dispensing system can be used to compensate the drifts in quality observed in presses when the speed, or any environmentable parameters vary.

This invention discloses an ink dispensing system for a printer using the nip area between the inking cylinder and the gravure/anilox cylinder as the sole source of inking. Our solution solves the problem of reducing the amount of ink present in the inking buffer, i.e. the nip area, of such printing machines, thereby accelerating the reaction time of an ink replacement and reducing the amount of waste and the cleaning time. The idea behind the invention is to provide ink to the nip area at selected locations when needed by using a dispensing apparatus that moves along the nip area.

Examples dis closed herein relate to identifying an amount of remaining supply of a print material, selecting one of a plurality of threshold ranges associated with the amount of remaining print material, and updating a visual indicator indicative of the selected one of the plurality of threshold ranges.

Methods of determining a level of a print substance in a print substance reservoir are disclosed. A reference capacitance of a reference sensor is measured. The reference capacitance is representative of one of a full print substance reservoir and an empty print substance reservoir. A level capacitance of a level sensor is measured. A correlation between the reference sensor and the level sensor is applied to the measured reference capacitance to determine an adjusted reference capacitance. A fill level ratio is determined based on the measured level capacitance and the adjusted reference capacitance.

A method of detecting a level of printable fluid in a container includes, with at least one sensing location on a die in thermal contact with the printable fluid in the container, sensing a voltage of a capacitor over time as current from the capacitor leaks through a field effect transistor (FET). The FET and capacitor are associated with the sensing location. The method may further include, based on the voltage of the capacitor over time and a threshold voltage, determining whether the printable fluid is present at the at least one sensing location.

A method to determine a quantity of a liquid in a container. In the method, a actuator is controlled to rotate a member in the container at a first speed. A measurement of electrical current drawn by the actuator at the first speed is received. A quantity of liquid in the container is determined through a look-up table and the measured electrical current.