Abstract: An example system includes a power supply. The power supply is electrically coupled to an electrode, a developer roller, and a cleaner roller. The system also includes a controller. The controller is to instruct the power supply to reduce, at a first time, a magnitude of an electrode voltage supplied to the electrode. The controller also is to instruct the power supply to set, at a second time, a developer roller voltage and a cleaner roller voltage each to about a wet null voltage.

Abstract: In one example of the disclosure, it is determined that an amount of print agent remaining in a print agent container of a print apparatus is below a threshold level. An amount of print solution is transferred from a print solution reservoir of the print apparatus, or an amount of print solution solvent is transferred from a solvent reservoir of the print apparatus, into the print agent container. At least some of the remaining print agent is caused to dissolve into the amount of print solution or print solution solvent to forma rinse solution. The rinse solution is transferred from the print agent reservoir to the print solution reservoir.

Abstract: In an example, a method for controlling termination of a print procedure subsequent to a node reset within print apparatus including a plurality of nodes includes identifying the node at which the reset occurred, and controlling operation within the print apparatus by way of a selected node. The selected node is different from the identified node and selected responsive to the identification of the identified node for operation of a component of the print apparatus as part of a termination procedure.

Abstract: According to examples, a method comprises receiving, at a processor, print job data relating to a print job to be performed by a print apparatus, the print job data defining order in which a plurality of colour separation images are to be transferred onto an imaging surface of the print apparatus. The method may comprise determining, based on the print job data, a number of null segments to be inserted into the print job and a location at which each null segment is to be inserted amongst the plurality of colour separation images. A print apparatus and a machine-readable machine are also disclosed.

Abstract: In an example, a method of controlling voltage applied to a print blanket within a printing device includes printing a print job. During the printing, a null cycle trigger is received. In response to the trigger, a print blanket bias voltage is reduced from a print bias level to a null bias level.

Abstract: In an example, a method of wetting a print blanket includes receiving a null cycle trigger during a printing session. The method also includes maintaining printing voltages on a forecast BID (binary ink developer) that has been prepared to print a next color separation onto a photoreceptor, and applying wet null voltages to a non-forecast BID. The method then includes engaging the non-forecast BID with the photoreceptor to transfer fluid other than ink to the photoreceptor during the null cycle.

Abstract: Certain examples described herein relate to splice detection. In certain cases, a splice is detected in a web being conveyed towards a transfer member of the printing system. In certain cases, a print frame is identified from a sequence of pending print frames using successive repeat lengths of the sequence and a distance of the splice from the transfer member. The identified print frame is to be transferred from the transfer member across the splice. In certain cases, writing of the identified print frame onto a photo-imaging plate of the printing system is deferred. In certain examples, the web is disengaged from the transfer member following transfer of an image of a print frame preceding the identified print frame. The web is re-engaged with the transfer member so as to transfer an image of the identified print frame to the web from the transfer member after the splice is conveyed beyond the transfer member.

Abstract: In an example, a method of controlling voltage applied to a print blanket within a printing device includes printing a print job. During the printing, a null cycle trigger is received. In response to the trigger, a print blanket bias voltage is reduced from a print bias level to a null bias level.

Abstract: An apparatus is provided for controlling a liquid electrophotography printer (LEP). The LEP may include a plurality of ink developers, IDs, to transfer charged ink to a photoreceptor, by virtue of a potential difference between the engaged ID and the photoreceptor selectively dischargeable to allow an image to be formed on a print medium in use through printing a spread of plural color separations thereon each corresponding to ink from one of a plurality of engaged IDs. the apparatus may comprise a print controller to, in use monitor an order of color separations to be printed onto the print medium.

Abstract: 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.

Abstract: In one example of the disclosure, it is determined that an amount of print agent remaining in a print agent container of a print apparatus is below a threshold level. An amount of print solution is transferred from a print solution reservoir of the print apparatus, or an amount of print solution solvent is transferred from a solvent reservoir of the print apparatus, into the print agent container. At least some of the remaining print agent is caused to dissolve into the amount of print solution or print solution solvent to forma rinse solution. The rinse solution is transferred from the print agent reservoir to the print solution reservoir.

Abstract: A photo drum may be to receive a color separation. A controller may be to change a location of the color separation on the photo drum from a first location to a second location when a separation location history for the color separation is outside of a threshold range.

Abstract: 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.

Abstract: In an example, a method of wetting a print blanket includes receiving a null cycle trigger during a printing session. The method also includes maintaining printing voltages on a forecast BID (binary ink developer) that has been prepared to print a next color separation onto a photoreceptor, and applying wet null voltages to a non-forecast BID. The method then includes engaging the non-forecast BID with the photoreceptor to transfer fluid other than ink to the photoreceptor during the null cycle.

Abstract: A photo drum may be to receive a color separation. A controller may be to change a location of the color separation on the photo drum from a first location to a second location when a separation location history for the color separation is outside of a threshold range.

Abstract: An apparatus is provided for controlling a liquid electrophotography printer (LEP). The LEP may include a plurality of ink developers, IDs, to transfer charged ink to a photoreceptor, by virtue of a potential difference between the engaged ID and the photoreceptor selectively dischargeable to allow an image to be formed on a print medium in use through printing a spread of plural colour separations thereon each corresponding to ink from one of a plurality of engaged IDs. the apparatus may comprise a print controller to, in use monitor an order of colour separations to be printed onto the print medium.

Abstract: In an example, a method of wetting a print blanket includes receiving a null cycle trigger during a printing session. The method also includes maintaining printing voltages on a forecast BID (binary ink developer) that has been prepared to print a next color separation onto a photoreceptor, and applying wet null voltages to a non-forecast BID. The method then includes engaging the non-forecast BID with the photoreceptor to transfer fluid other than ink to the photoreceptor during the null cycle.

Abstract: In an example, a method of controlling voltage applied to a print blanket within a printing device includes printing a print job. During the printing, a null cycle trigger is received. In response to the trigger, contact between a print blanket and an impression drum is reduced.

Abstract: In one example, an electrostatic printer includes: a photoconductor member; a charging unit to charge the photoconductor member to a charged voltage; an imaging unit to generate a latent electrostatic image on the photoconductor member by discharging areas of the charged photoconductor member; a developer unit to develop a toner image on the photoconductor member using a developer voltage; and a controller to change the developer voltage and to change the charged voltage dependent on the change of the developer voltage to keep the difference between the developer voltage and the charged voltage constant.

Abstract: A photo drum may be to receive a color separation. A controller may be to change a location of the color separation on the photo drum from a first location to a second location when a separation location history for the color separation is outside of a threshold range.