Disclosed is a print offset determining apparatus. The apparatus is to receive information indicative of a position of an imaging element relative to a binary ink developer when the binary ink developer comes into contact with the imaging element and determine an offset between the position of the imaging element and a reference position of the imaging element relative to the binary ink developer.

A positioning device to control the position of a print agent applicator comprises a mount to support a print agent applicator at a load point on the mount; an actuator coupled to the mount to apply a driving force at an actuation point on the mount; and a guide mechanism to guide the mount and supported print agent applicator, under the driving force, to translate along a predetermined path towards a printing drum to form an engaging contact between the print agent applicator and the printing drum.

In one example in accordance with the present disclosure, a developer unit seal is described. The developer unit seal includes an endcap. The endcap has an opening to receive a dynamic seal for a roller, an inlet to receive print fluid, and a channel embedded in a surface of the endcap. The channel connects the inlet with the opening to direct print fluid to the opening. The developer unit seal also includes a sealing member to cover the channel.

A liquid electrophotographic (LEP) printing device that includes a photo-imaging plate (PIP) to receive a liquid printing fluid, the liquid printing fluid including a pigment incorporated into a resin, a charge conductor, and a carrier liquid, and a transfer roller to transfer the liquid printing fluid from the PIP to a fabric substrate while wet.

Disclosed is a method to mitigate deterioration of printing fluid in a tank of a printer. The method comprises: draining printing fluid from a tank of a printer, and stopping the draining before the tank is empty, wherein the printing fluid comprises solids suspended in imaging oil, filtering the printing fluid drained from the tank, to separate at least some of the solids from the imaging oil, passing the filtered imaging oil to a reservoir; and then passing imaging oil from the reservoir to the tank. Also disclosed is a printer and a system to perform the method.

In an image forming apparatus, in a case where a power of the apparatus is turned from OFF to ON, a rotation drive unit rotationally drives each of a developing roller, a first conductive roller, and a second conductive roller in a state where a liquid developer supplied to a developer container by a supply device has reached a supply position, and a bias application unit applies a bias to each of the developing roller, the first conductive roller, and the second conductive roller after the developing roller rotates at least once, in the state where the liquid developer supplied to the developer container by the supply device has reached the supply position.

A printing drum for a liquid electrophotographic printing system which comprises a photosensitive surface and a heating device mounted to the printing drum. The heating device heats the photosensitive surface of the printing drum to a predetermined temperature.

An image forming apparatus includes a first container to accommodate liquid developer for replenishment to a developing container, and a second container to accommodate carrier fluid containing a charge control agent for replenishment to the first container. The concentration of the charge control agent in the carrier fluid accommodated in the second container is between equal to or more than 10 wt % and equal to or less than 20 wt %. A driving unit is driven so as to replenish the charge control agent accommodated in the second container to the first container, and a control unit controls the driving unit based on image coverage of an output image so that a concentration of the charge control agent in the liquid developer accommodated in the first container becomes a predetermined value.

Certain examples of seals that can move along a slit are disclosed. The seals can comprise a first leaf, a second leaf, and a biasing member to push the first leaf away from the second leaf. Also, apparatus for applying a fluid, and printing systems are described.

An image forming apparatus includes an image bearing member; a transfer member configured to form a transfer portion where the toner image is transferred from the image bearing member by being supplied with a transfer bias; a carrier liquid supplying portion configured to supply the carrier liquid to the transfer portion; a transfer bias voltage source capable of applying the transfer bias to the transfer portion; a detecting portion configured to detect at least one of a voltage and a current at the transfer portion; and a setting portion configured to set the transfer bias during non-image-formation on the basis of a detection result of the detecting portion when a setting bias is applied from the transfer member in a state in which the carrier liquid is in the transfer portion.