A developing apparatus includes a body; a buffer plate on the body and including a gas flow path; a vacuum plate on an upper surface of the buffer plate and having a gas supply hole in fluid communication with the gas flow path; and a slit block on an edge of the vacuum plate, the slit block and the vacuum plate forming a flow path for gas from the gas supply hole, wherein a substrate is holdable on the vacuum plate, a contact area between the substrate and the vacuum plate being 90% or more of an area of the substrate, the slit block and the vacuum plate form a buffer space and an inclined first flow path in fluid communication with the buffer space, and the slit block and an edge of the substrate forms a second flow path in fluid communication with the first flow path.

An example method of performing a null cycle in a liquid electrographic printer is described. The method involves collecting, at a photo imaging plate cleaning station, imaging oil deposited on a photo imaging plate during a print cycle. During a null cycle, the photo imaging plate cleaning station is controlled to apply the collected imaging oil to the photo imaging plate.

Measures for controlling an engagement force between a photo imaging plate and a developer roller in a printing device are described. A motor is operated to generate rotational motion. The rotational motion is translated into linear motion. The linear motion causes an adjustment to the engagement force between the developer roller and the photo imaging plate. A characteristic of the motor is monitored. The motor is controlled on the basis of the monitored characteristic in order to maintain a desired engagement force between the developer roller and the photo imaging plate.

A print agent transfer assembly including a print agent transfer member to receive a first layer and a second layer of print agent, and an energy source to provide energy at a first predetermined intensity level to the first layer and to provide energy at a second, different predetermined intensity level to the second layer.

An example method of printing images in an electrophotographic printer is provided. The method includes developing a first image on a first portion of an intermediate transfer member by receiving a first sequence of color separations from a photo imaging member, and developing a second image on a second portion of the intermediate transfer member by receiving a second sequence of color separations from the photo imaging member. A voltage is applied to the intermediate transfer member during receipt of each color separation from the photo imaging member. During development of the second image at least one null separation is inserted into the second sequence of color separations. During a period for the null separation, a voltage applied to the intermediate transfer member is reduced and the first image is transferred to a conductive substrate.

A technique includes rotating a squeegee roller to regulate a film thickness of ink on a developer roller; and using the developer roller to transfer a portion of the ink from the developer roller to a photoconductive member. The technique includes creating, by an electrode, a potential bias with the developer roller to transfer the ink to the developer roller; and inhibiting flow streaks on the developer roller, where inhibiting the flow streaks includes restricting a flow of ink between the squeegee roller and the electrode.

A developer container is capable of supplying a liquid developer to a portion, of a surface of a cleaning roller, between a cleaning position X and a contact position Y with respect to a rotational direction of the cleaning roller. A free end of a cleaning blade is positioned in a range of 65 or more and less than 95 as a positive angle of the rotational direction of the cleaning roller when a line passing through a center of the cleaning roller and an upper end portion of the cleaning roller with respect to a direction of gravitation is at 0 (reference line G). In this case, the cleaning blade is disposed so that an angle between a line F perpendicular to a line E connecting the center of the cleaning roller and the free end of the cleaning blade, and the cleaning blade is in a range of 35 or more and less than 60 .

In one aspect an apparatus for use in an electrographic printer is described. The apparatus includes a housing having a base, a first wall, and a second wall, wherein the housing defines a cavity. The apparatus also includes a developer roller and an ink developer electrode for developing ink to the developer roller. The apparatus also includes an ink outlet, and a gutter for directing ink in the cavity towards the ink outlet, the gutter being disposed between the first wall and second wall, and between the developer roller and base. The gutter has a floor, a first side, and a second side, each extending along a length of the gutter. The floor slopes towards the ink outlet to direct ink towards the ink outlet, and the floor and sides of the gutter form a curve transverse to the length of the gutter to direct ink towards the floor.

In one aspect an apparatus (200) for use in an electrographic printer (100) is described. The apparatus includes a housing (210) defining a cavity (220), a developer roller (250), a developer electrode (240) for developing printing substance onto the developer roller, the electrode being arranged within the cavity, and a heater (260) for heating printing substance to be developed onto the developer roller, the heater being arranged in the cavity.

Example implementations provide a method of controlling an ink developer used in electro-photography; the method comprising, following cessation of printing, varying a plurality of voltages associated with movement of ink within the ink developer at temporally disparate times.