A liquid electrophotographic ink developer comprises a developer roller (112) rotatable about an axis, first and second electrodes (108, 110) proximate the developer roller (112) and an inlet chamber (100) extending along the axis from a first end adjacent an inlet opening (122) to a second end opposite the first end. A neck (104) forms an uninterrupted ink flow path from the inlet chamber (100) to the developer roller (112).

Ink-based digital printing systems useful for ink printing include a rotatable charge-retentive reimageable surface layer configured to receive a layer of fountain solution. The fountain solution is carried to the charge retentive surface by a fog or mist including fountain solution aerosol particles, dispersed gas particles, and charge directors that impart charge to the fountain solution aerosol particles. The charge-retentive reimageable surface may be charged to a uniform potential, and selectively discharged using an ROS according to image data to form an electrostatic latent image. The charged fountain solution adheres to portions of the charge-retentive reimageable surface according to the electrostatic latent image to form a fountain solution image thereon. The fountain solution image can be partially transferred to an imaging blanket, where the fountain solution image is inked. The resulting ink image may be transferred to a print substrate.

According to one example, there is provided an imaging system that comprises a housing, a rotatable polygon comprising multiple mirrored facets located in the housing, a laser to generate a laser beam to shine onto the polygon mirror and to reflect onto a target, and wherein, in use, the density of gas within the housing is such that turbulence-related optical distortion within the housing is not greater than a predetermined limit.

An imaging system includes a casing with a developing chamber, a developing roller which is located inside the developing chamber and which carries a toner, and a conveying path which is located adjacent to the developing chamber inside the casing and is used to circulate the toner and to supply the toner to the developing roller. A discharge path includes an inlet, an outlet, and an intermediate portion between the inlet and the outlet. The inlet communicates with the developing chamber in the casing and is located outside the conveying path. The outlet is located between the developing roller and a photoreceptor. The intermediate portion is located outside the casing.

An example printing fluid apparatus, for a printing system, comprises a printing fluid reservoir to store printing fluid for use in a print job and a printing fluid channel to route printing fluid from the reservoir to the reservoir and to route printing fluid from a printing station of the printing system to the reservoir. The fluid channel comprises a port to introduce printing fluid from a printing fluid cartridge into the fluid channel such that the introduced printing fluid from the printing fluid cartridge at least partially mixes with printing fluid in the fluid channel.

A toner melt-kneading apparatus to perform melt-kneading includes a kneading chamber, a discharge member connected to the kneading chamber, and a pressure gauge provided to the discharge member. The discharge member includes a flow passage having a substantially cylindrical shape and configured to pass a kneaded material. The pressure gauge includes a thermometer and includes a pressure-measuring portion disposed in the flow passage. D, d, and ϕ satisfy the following relationship, where a length of the flow passage is denoted as D, a distance from a discharge port in a downstream-side end portion of the discharge member to the pressure-measuring portion is denoted as d, and an inner diameter of the flow passage is denoted as ϕ, 0.020≤(d/D)/ϕ (herein, D>d).

In one example of the disclosure, a developer system includes a housing and a developer roller. A first electrode and a second electrode are disposed in the housing, the first and second electrodes to create an electrical charge to cause transfer of printing fluid to a developer roller surface. The developer roller is rotatably connected to the housing. The developer includes a surface, a bearing to support and enable rotation of an axle attached to the developer roller, and a plurality of stop pins. The plurality of stop pins are connected to the housing. The stop pins are to support the bearings and to establish target distances between the developer roller surface and the first electrode and second electrodes.

Examples described herein relate to a print substance container consistent with the disclosure. For instance, the print substance container may comprise a print substance disposed inside of the print substance container and a first electromagnet formed of a wire coil positioned around the print substance container and extending along a length of the print substance container.

In an example of the disclosure, carrier liquid is supplied to a container with a set of walls defined at least partially by a surface of an electrode. The carrier liquid is caused to move through a container via a carrier liquid flow path to sequentially encounter a set of accumulation elements. Each accumulation element is situated between adjacent walls. A voltage is applied to the electrode to generate an electric field between the electrode surface and the set of accumulation elements. The electric field causes contaminant from the carrier liquid to adhere to the set of accumulation elements.

A photoconductor marking apparatus is disclosed. The apparatus includes a radiation source to emit radiation capable of irreversibly modifying photoconductive properties of a layer of a multi-layered photoconductor. The apparatus also includes processing apparatus to: determine a pattern to be applied to a photoconductor to be used in a print apparatus, the photoconductor having an imaging area within which print agent is to be deposited; and control the radiation source to direct radiation towards the photoconductor in a region outside the imaging area, so as to irreversibly modify photoconductive properties of a layer of the photoconductor according to the determined pattern. A method and a machine-readable medium are also disclosed.