In an example, a method includes collecting (102) print agent from a print agent reservoir to form a print agent layer on a first print agent transfer member (204). The print agent layer may be transferred (104) directly from the first print agent transfer member to a second print agent transfer member (206), where the print agent layer may be heated (106). The print agent layer may be applied (108) directly from the second print agent transfer member to a substrate.

An image forming apparatus includes a toner charge amount predictor, a toner developing resistance calculator, and a determiner. The toner developing resistance calculator calculates a toner developing resistance on the basis of a bias voltage applied to a developing device and a measured developing current by dividing a value of the bias voltage by a value of the developing current when a developing device develops an electrostatic latent image formed on the surface of an image carrier to form a toner image. The toner charge amount predictor predicts a toner charge amount of a toner which is supplied to the image carrier by the developing device on the basis of a density of the toner image and the developing current. The determiner determines a state of the developing device on the basis of the toner charge amount and the toner developing resistance.

An image forming apparatus includes a photosensitive member, a light source, a light guiding unit including a light guiding member, a casing portion provided with a first through hole, and a sheet-like elastic member provided with a second through hole. The light guiding unit penetrates the first through hole and the second through hole, and one end portion of the light guiding unit opposes the light source and is positioned inside the casing portion. In a flat surface of the light guiding unit perpendicular to a longitudinal direction of the light guiding unit, an area of the second through hole is smaller than an area of the light guiding unit.

A printing device having a heating apparatus arranged to heat an image substrate, a temperature sensor associated with the image substrate, and a processor communicatively coupled to the heating apparatus. During a simulation mode of the printing device, the processor determines the heating power of the heating apparatus, predicts a temperature of the image substrate based on the heating power, compares the predicted temperature to a measured temperature of the image substrate by the temperature sensor, determines a calibration offset when the measured temperature deviates from the predicted temperature, and selectively generates a control signal for use in calibrating the temperature sensor based on the calibration offset.

A printing device containing a heating apparatus that heats an image substrate, a temperature sensor associated with the image substrate and a processor communicatively coupled to the heating apparatus. The processor determines the heating power of the heating apparatus, compares the heating power to a predetermined power range, determines a status of the temperature sensor when the heating power is outside the predetermined power range, and triggers a response mode of the printing device based on the determined status of the temperature sensor.

A toner cartridge according to one example embodiment includes a developer roll and a toner adder roll. First and second drive gears are rotatably connected to and coaxial with the developer roll and toner adder roll, respectively. The toner cartridge includes a drive coupler exposed to receive rotational motion when the toner cartridge is installed in an image forming device. Gear teeth of the first drive gear are directly meshed with gear teeth of the drive coupler of the toner cartridge. The second drive gear is rotatably connected to the drive coupler through a pair of idler gears.

In certain examples, a liquid electrophotographic printer has a charge erasing element and a charging element. The charge erasing element at least partially discharges a charged photo imaging plate and a charged layer of liquid toner and the charging element at least partially recharges the layer of liquid toner and the photo imaging plate.

A fixing device includes: a fixing member that heats a toner image formed on a recording sheet in order to fix the toner image on the recording sheet; a pressurizing member that nips the recording sheet together with the fixing member to pressurize the toner image on the recording sheet; a heater that heats the pressurizing member; and a hardware processor that controls a heating temperature of the pressurizing member by the heater, wherein the hardware processor acquires setting of glossiness of the toner image and controls the heating temperature to be higher as the glossiness in the setting is lower.

In one example, a system for transferring an image from a photoconductor to a print substrate includes a transfer member having a removable blanket wrapped around a rotatable drum and a laser. The blanket has a light absorbing exterior surface to receive a liquid LEP ink image from the photoconductor and to release a layer of molten toner to a print substrate. As the drum rotates, the laser exposes a width of the exterior surface of the blanket carrying a liquid LEP ink image to a beam of coherent light that delivers enough power to transform the liquid LEP ink image into molten toner.

Disclosed is a heat source for radiating heat onto an intermediate printing material transfer element of a printing apparatus. The heat source comprises a plurality of heat generating segments disposed along an axis, the plurality of heat generating segments including a first heat generating segment, a second heat generating segment and a third heat generating segment. The second heat generating segment is disposed between the first heat generating segment and the third heat generating segment. The second heat generating segment has a length shorter than a length of the first heat generating segment and shorter than a length of the third heat generating segment. Also disclosed is a printing system comprising the disclosed heat source. Also disclosed is a method of selecting a heat radiating pattern of a heat source.