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.

A development device, includes: a developer bearing member; a magnet that is stored in the developer bearing member and has a development pole; and a regulation portion that is disposed to face the developer bearing member for regulating an amount of developer carried on the developer bearing member, wherein the regulation portion is disposed such that, when a magnetic flux density of the development pole in the normal direction with respect to a surface of the developer bearing member is defined as positive, a magnetic flux density becomes positive in the entirety of a region which is upstream of a development region where the developer and an image bearing member are in contact with each other so as to develop an electrostatic latent image formed on the image bearing member and which is downstream of the regulation portion in a rotation direction of the developer bearing member.

Example implementations relate to a printing an image on a substrate and printing an ultraviolet-sensitive finishing mark on the substrate using ultraviolet-sensitive ink. The ultraviolet-sensitive finishing mark can be visible under ultraviolet light.

A thermally conductive pipe includes a pipe having closed both end portions; a working fluid that is enclosed in inside of the pipe and that is vaporized and liquefied; and a liquid transfer member that extends in a longitudinal direction of the inside of the pipe and that transfers the liquefied working fluid at least in the longitudinal direction. An occupancy rate of a cross-sectional area of the liquid transfer member to a cross-sectional area in a transverse direction of the inside of the pipe is in a range of 20% or more and 50% or less.

Described herein is a liquid electrostatic ink developer assembly comprising a developer roller having a surface coating, the surface coating comprising a polyurethane resin formed from a polyol; a hydroxyl-terminated polysiloxane; and a polyisocyanate. Also, described herein is a liquid electrostatic printing apparatus comprising the liquid electrostatic ink developer assembly.

In an example, a method includes determining an indication of pixel separation for an image region to be printed to a substrate. A power level of a laser light source to address a pixel on a region of a photoconductive surface corresponding to the image region may be adjusted based on the indication of pixel separation to compensate for print spot size variation associated with pixel separation.

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

An image formation device includes a transfer member and a first portion to receive an electrically charged, image-receiving holder onto the transfer member. A second portion downstream from the first portion is to receive droplets of ink particles within a dielectric carrier fluid onto the electrically charged, image-receiving holder to form at least part of an image. A charge source is to emit airborne charges to charge the ink particles to move, via attraction relative to the image-receiving holder, through the carrier fluid to become electrostatically fixed relative to the image-receiving holder. A liquid removal unit is to remove at least the carrier fluid from at least a surface of the image-receiving holder. A transfer station is to transfer the ink particles of the image and the image-receiving holder together from the transfer member to an image formation medium.

A thermally conductive pipe includes a pipe having closed both end portions; a working fluid that is enclosed in inside of the pipe and that is vaporized and liquefied; and a liquid transfer member that extends in a longitudinal direction of the inside of the pipe and that transfers the liquefied working fluid at least in the longitudinal direction. An occupancy rate of a cross-sectional area of the liquid transfer member to a cross-sectional area in a transverse direction of the inside of the pipe is in a range of 20% or more and 50% or less.