An image forming apparatus includes a power supply board, a driver board, and an engine control board. The driver board includes a plurality of switching elements each configured to supply and shut off a power supply for each of a plurality of distributed power supply voltages supplied from the power supply board. The plurality of switching elements includes a first switching element, to which the power supply voltage is to be applied from the power supply board, and a second switching element, to which the power supply voltage output from the first switching element is to be applied in a distributed manner. The engine control board is configured to performs failure diagnosis of the first switching element when the image forming apparatus is activated, and performs failure diagnosis of the second switching element in a case where an abnormality has occurred in any one of a plurality of loads.

An image forming apparatus includes a power supply board, a driver board, and an engine control board. The driver board includes a plurality of switching elements each configured to supply and shut off a power supply for each of a plurality of distributed power supply voltages supplied from the power supply board. The plurality of switching elements includes a first switching element, to which the power supply voltage is to be applied from the power supply board, and a second switching element, to which the power supply voltage output from the first switching element is to be applied in a distributed manner. The engine control board is configured to performs failure diagnosis of the first switching element when the image forming apparatus is activated, and performs failure diagnosis of the second switching element in a case where an abnormality has occurred in any one of a plurality of loads.

A developing device for forming an image by developing an electrostatic latent image formed on an image carrier with a developer, includes: a developing container that accommodates the developer; a developing roller that faces the image carrier, is disposed adjacent to the developing container, and conveys the developer accommodated in the developing container to the image carrier, and a developer discharging part that is provided in the developing container and discharges a part of the developer, wherein a discharge amount of the developer discharged by the developer discharging part is controlled on the basis of a charge amount of a toner included in the developer.

A system and method for printing includes a transfer belt configured to transfer toner from a photoconductive drum of a toner-based printer to a paper. A transfer platen positions at least a portion of the transfer belt to be in proximity to a photoconductive drum. For color printing, a transfer platen is associated with a corresponding photoconductive drum for each distinct color of toner. The transfer platen is shaped to improve the transfer of toner from the photoconductive drum to the transfer belt. The transfer platen is substantially fixed in a non-rotatable position. The transfer platen includes electrically conductive foam. The transfer platen includes a low friction conductive top layer over the electrically conductive foam.

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.

An image forming apparatus includes a first image forming portion including a first photosensitive member, a first charging member, and a first developing member including a first accommodating portion: a second image forming portion including a second photosensitive member, a second charging member, and a second developing member including a second accommodating portion: an exposure portion; an applying portion: a storing portion; and a controller. When in the storing portion, information on toner accommodated in the first accommodating portion is changed from first information to second to information and information on toner accommodated in the second accommodating portion is not changed, the controller carries out control so that a transfer voltage is changed from a first transfer voltage to a second transfer voltage and so that a potential of an image portion formed on the second photosensitive member is changed from a first potential to a second potential.

A heating member of a fixing unit is situated in a fixing portion, and a commercial power source applies an alternating-current voltage to the heating member so that the heating member heats a transfer medium held in the fixing portion. In a case of transferring the toner image from an image bearing member onto the transfer medium in a transfer portion, a control unit controls a transfer power source based on a result of a comparison between a frequency obtained from a first detection result input from a detection unit with a predetermined frequency range including the frequency of the alternating-current voltage.

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.

A system and method for printing includes a transfer belt configured to transfer toner from a photoconductive drum of a toner-based printer to a paper. A transfer platen positions at least a portion of the transfer belt to be in proximity to a photoconductive drum. For color printing, a transfer platen is associated with a corresponding photoconductive drum for each distinct color of toner. The transfer platen is shaped to improve the transfer of toner from the photoconductive drum to the transfer belt. The transfer platen is substantially fixed in a non-rotatable position. The transfer platen includes electrically conductive foam. The transfer platen includes a low friction conductive top layer over the electrically conductive foam.

In one example, a method for calibrating a position of a charge roller is described. The method may include a processor positioning a first end of a charge roller to a first plurality of index positions, determining a capacitance between the charge roller and a photoconductor imaging plate at each of the first plurality of index positions, determining a first index position of the first plurality of index positions with a greatest change in capacitance, and calibrating a position of the charge roller based upon the first index position.