An ultra-high resolution capacitive sensor affixed above an imaging member surface measures the thickness of fountain solution on the imaging member surface in real-time during a printing operation. The sensor is considered ultra-high resolution with a resolution high enough to detect nanometer scale thicknesses. The capacitive sensor would initially be zeroed to the imaging member surface. As fluid is added, the capacitive sensor detects the increase and can measure and communicate with the image forming device to adjust fountain solution flow rate to the imaging member surface and correct for any anomalies in thickness. This fountain solution monitoring system may be fully automated. The capacitive sensor may have a resolution (e.g., as low as about 1 nm resolution) of about 0.001% of the distance/gap that the capacitive sensor is mounted away from the imaging member surface.

A coefficient of friction (COF) sensor on a carrier roll surface wetted with fountain solution transferred from an imaging member measures COF of the wetted carrier roll surface in real-time, even between or during printing operations. The transferred fountain solution may be concentrated and/or chilled to solidify before the measurement. The measured COF is used in a feedback loop to actively control the fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during an imaging or other printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

A coating device for supplying a liquid to a substrate, particularly in the form of an optionally printed web, foil, strip or sheet, comprises a reservoir for holding a quantity of liquid. Coating means are provided which are able and configured to take liquid from the reservoir and transfer it to the substrate. Supply means deliver the liquid into the reservoir during operation. The supply means are controllable and are able to lead a constant liquid flow into the reservoir. The reservoir is provided with level detecting means which are able and configured to detect a liquid level in the reservoir. Provided between the level detecting means and the coating means is a control which controls the coating means during operation on the basis of a detection (LS) of the liquid level in the reservoir in order to maintain the liquid level at a fixed value.

Examples disclosed 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.

Provided is an electromagnetic wave generator including: an electromagnetic wave generation section that generates an electromagnetic wave; a high-frequency voltage generation section that generates a voltage applied to the electromagnetic wave generation section; and a transmission line that electrically couples the electromagnetic wave generation section and the high-frequency voltage generation section to each other, in which the electromagnetic wave generation section includes a first electrode, a second electrode, a first conductor that electrically couples the first electrode and the transmission line to each other, and a second conductor that electrically couples the second electrode and the transmission line to each other, one of the first electrode or the second electrode is a reference potential electrode to which a reference potential is applied and the other is a high-frequency electrode to which a high-frequency voltage is applied, a minimum separation distance between the first electrode and the second electrode is 1/10 or less of a wavelength of an output electromagnetic wave, a minimum separation distance between the first conductor and the second conductor is 1/10 or less of a wavelength of an output electromagnetic wave, and the first conductor further includes a coil, and the coil is closer to the first electrode than the transmission line.

A coefficient of friction (COF) sensor on a carrier roll surface wetted with fountain solution transferred from an imaging member measures COF of the wetted carrier roll surface in real-time, even between or during printing operations. The transferred fountain solution may be concentrated and/or chilled to solidify before the measurement. The measured COF is used in a feedback loop to actively control the fountain solution layer thickness by adjusting the volumetric feed rate of fountain solution added onto the imaging member surface during an imaging or other printing operation to reach a desired uniform thickness for the printing. This fountain solution monitoring system may be fully automated.

A doctor blade holder and adjustment mechanism that may be utilized with a flexographic printing system. The doctor blade holder and adjustment mechanism may utilize a constant displacement of the doctor blade against an anilox roller, rather than a constant force, to reduce ink build up on the back side of the doctor blade, and subsequently, intermittent dropping of the accumulated ink onto the post-shearing side of the anilox roller (“spitting”). The doctor blade holder and adjustment mechanism may provide adjustability of a combination of doctor blade pressure, angle and displacement.

An ink replenishment system for a can decorator having a plurality of ink fountains corresponding to a plurality of ink station assemblies includes a robotic arm structured to pick up ink from a selected one of a plurality of ink container and to place the picked up ink into a selected one of the plurality of ink fountains, and a controller structured to control operations of the robotic arm.

An ultra-high resolution capacitive sensor affixed above an imaging member surface measures the thickness of fountain solution on the imaging member surface in real-time during a printing operation. The sensor is considered ultra-high resolution with a resolution high enough to detect nanometer scale thicknesses. The capacitive sensor would initially be zeroed to the imaging member surface. As fluid is added, the capacitive sensor detects the increase and can measure and communicate with the image forming device to adjust fountain solution flow rate to the imaging member surface and correct for any anomalies in thickness. This fountain solution monitoring system may be fully automated. The capacitive sensor may have a resolution (e.g., as low as about 1 nm resolution) of about 0.001% of the distance/gap that the capacitive sensor is mounted away from the imaging member surface.

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.