An image forming device is provided that more effectively reduces changes in the image density caused by reductions in the charged potential immediately after the application of charge to a photosensitive body, including: a photosensitive body; a charger that charges the photosensitive body; a charged potential fluctuation prediction unit that predicts an amount of fluctuation in a charged potential of the photosensitive body; an optical scanning device that irradiates the photosensitive body with an exposure laser and forms an electrostatic latent image; a development device that develops the electrostatic latent image; and an exposure laser output correction unit that corrects an output of the exposure laser. The charged potential fluctuation prediction unit predicts an amount of fluctuation in the charged potential from a charging stop time, and the exposure laser output correction unit reduces a change in density of the image caused by a fluctuation in the charged potential.

A transfer nip is formed between a transfer member and a photosensitive drum. The transfer member is configured to transfer a toner image formed on the photosensitive drum to a sheet that passes through the transfer nip. A humidity sensor is configured to detect humidity. A sheet sensor is arranged upstream of the transfer member in a sheet conveyance direction. The sheet sensor is configured to detect a trailing end of the sheet. A controller is configured to: in response to an elapse of a particular period after the sheet sensor detects the trailing end of the sheet, change a transfer bias to be applied to the transfer member from a first transfer bias to a second transfer bias, the second transfer bias having a smaller absolute value than the first transfer bias; and change the particular period based on the humidity detected by the humidity sensor.

An image forming system includes an image forming unit configured to form an image on a recording medium; a feeding unit on which the recording medium is placed and configured to convey the recording medium toward the image forming unit on a conveyance path; an insert unit on which an insert sheet is placed and configured to convey the insert sheet so as to insert the insert sheet between a plurality of recording mediums conveyed from the image forming unit; a storage unit configured to store information concerning feeding of the recording medium; and a control unit configured to control a feeding timing of the insert sheet by the insert unit based on the information stored in the storage 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.

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.

According to an embodiment, a fixing device includes rotating body that is rotatably supported, a heater that heats the rotating body, a pressing body that is pressed against the rotating body to form a nip through which print media passes to a media conveyance path, and a water vapor discharge passage downstream of the nip from rotating body. The water vapor discharge passage is separate and distinct from the media conveyance path. The fixing device may be used in image forming apparatuses and the like.

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.

A first supply mode is a mode for supplying power so that printing can be performed by a printing unit, and more power is supplied in the first supply mode than in the second supply mode or the third supply mode. More power is supplied in the second supply mode than in the third supply mode. In the specified period, the power supply circuit switches from the power supply in the first supply mode to the power supply in the second supply mode when a first transition condition is satisfied. The power supply circuit maintains the second supply mode without performing switching from the power supply in the second supply mode to the power supply in the third supply mode.

An image forming apparatus includes an image forming unit, a storage portion to which a heating unit configured to heat the sheet stored in the storage portion is detachably attached, a conveyance unit, a detection unit configured to detect attachment of the heating unit to the storage portion, and a control unit configured to control the conveyance unit such that a standby time by which conveyance of the sheet fed from the storage portion is stopped is shorter when the detection unit detects the heating unit than when the detection unit does not detect the heating unit.

An image forming apparatus includes an image forming portion, a first storage portion to which a first heating unit configured to heat the sheet of the first storage portion is detachably attached, a second storage portion to which a second heating unit configured to heat the sheet of the second storage portion is detachably attached, and an input portion configured for an operator to input information on attachment of the first heating unit to the first storage portion, and information on attachment of the second heating unit to the second storage portion.