An image forming apparatus includes: a plurality of image holding units that include first and second image holding units and on which toner images are formed through developing while the image holding units rotate; a plurality of developing units that respectively face the plurality of image holding units and develop an electrostatic latent image on each of the plurality of image holding units with toner under a developing bias voltage applied to each developing unit; a power supply unit that applies a developing bias voltage to the plurality of developing units, and is common to the plurality of image holding units; an intermediate transfer unit that receives transfer of a toner image from the plurality of image holding units and transfers the toner image to a transfer receiver while circulating in a circulation path including a moving path along the plurality of image holding units, the intermediate transfer unit having first and second modes, wherein in the first mode, the intermediate transfer unit receives transfer of a toner image from the plurality of image holding units, and in the second mode, the intermediate transfer unit is separated from the second image holding unit other than the first image holding unit and receives transfer of a toner image from the first image holding unit; and a driving unit that drives rotation of the plurality of image holding units, wherein in the second mode, the driving unit drives the second image holding unit so as to temporally change a position at which the second image holding unit faces the developing unit.

An image forming apparatus includes a transfer member to transfer a toner image borne on s photosensitive member onto a conveyed recording material on receiving voltage from a power supply. Where an image is formed at a transfer portion on a first recording material and a subsequent second recording material, a time interval is changed to a first or second interval based on information concerning the transfer onto the first recording material. The second recording material has a second width greater than a first width of the first recording material. The time interval is from when a first recording material trailing edge passes through the transfer portion to when a second recording material leading edge reaches the transfer portion. The photosensitive member rotates one or less rotations during the first interval and rotates one or more rotations during the second interval.

An image forming apparatus includes: an image holding section; a transfer section that has a transfer member, applies a transfer electric-field to a transfer region between the image holding section and the transfer member, and electrostatically transfers an image held by the image holding section onto a recording medium; contact sections that act as electrodes to ground while being in contact with the recording medium; a humidification section that is provided upstream of the transfer region and humidifies the recording medium; a first control section that performs control without humidification by the humidification section; a second control section that performs control to cause the humidification section to humidify the recording medium; and a selection section that selects the first control section or the second control section depending on a type of the recording medium.

An image forming apparatus includes: an image forming device configured to form an image on a sheet; a fan configured to be driven to perform ventilation; and at least one controller configured to function as: a unit configured to store flag information indicating a state where a dew condensation countermeasure is required in a non-volatile memory; a unit configured to restrict image formation by the image forming device and execute dew condensation countermeasure processing to cause the fan to perform predetermined driving; and a unit configured to delete, from the non-volatile memory, the flag information upon completion of the dew condensation countermeasure processing, wherein the controller executes the dew condensation countermeasure processing upon activation of the image forming apparatus based on at least storage of the flag information in the non-volatile memory.

A controller is configured to execute a larger gamut technology mode in which the controller performs image formation by controlling a ratio of a rotation speed of a development roller to a rotation speed of a photosensitive drum such that the ratio becomes a second speed ratio higher than a first speed ratio in a normal mode. The controller is configured to, when the controller executes the larger gamut technology mode, control transfer voltage based on a humidity around an image forming apparatus.

An image forming apparatus includes an image forming portion, a fixing portion, a duct and a water vapor moving portion through which water vapor generated in the fixing portion moves. The water vapor moving portion is cooled by air blowing in the duct.

Disclosed is a sheet feeding apparatus configured to be attached to an image forming apparatus. The sheet feeding apparatus includes a frame body and a locking member provided on an upper part of the frame body, the locking member being configured to be movable between a locking position where the frame body is locked to the image forming apparatus and a releasing position where the locking of the frame body is released, wherein in attaching the heating unit to an attaching position of the frame body, the locking member is configured to restrict a movement of the heating unit to the attaching position by interfering with the heating unit when the locking member is located at the releasing position and to allow a movement of the heating unit to the attaching position when the locking member is located at the locking position.

An image forming apparatus includes a heater and a controller. The heater includes a plurality of heater elements arranged in a main scanning direction to fix an image on a sheet passing a nip. The controller is configured to determine image-forming regions and non-image-forming regions among sheet regions of the sheet divided in the main scanning direction and a sub-scanning direction based on image data of the image. The controller is further configured to determine, as heating regions, the image-forming regions and a first part of the non-image-forming regions satisfying a predetermined condition, and determine, as non-heating regions, a second part of the non-image-forming regions not satisfying the predetermined condition. The controller is configured to energize one or more of the heater elements corresponding to the heating regions, selectively at timing when the heating regions pass the nip.

An image forming apparatus includes a photosensitive member, a first charging roller, a first cleaning member, a second charging roller, and a second cleaning member. The following relationship is satisfied:
(XL0+L1+L2)(YL3+L4)0
where L0 represents a length of a whole circumference of the first charging roller, L1 represents a length between a first contact area and a first contact position of the first charging roller and the photosensitive member, L3 represents a length of a whole circumference of the second charging roller, L4 represents a length between a second contact area and a second contact position, L2 represents a length between the first contact position and the second contact position, X represents an integer in a range of 0X40, and Y represents an integer in a range of 0Y40.

In an image forming apparatus, a removal unit includes a sheet member that has elasticity and contacts a rotator, and an absorption member that is thicker than the sheet member and arranged opposite to the rotator via the sheet member to absorb a water droplet, and the absorption member absorbs the water droplet removed by the sheet member from the rotator.