An image forming apparatus includes a stacking unit for stacking types of envelopes, an image forming unit that forms an image on a conveyed envelope, a rear-end regulating plate, provided on the stacking unit, that regulates a trailing end of the stacked envelope at an upstream side of a conveyance direction, side regulating plates, provided on the stacking unit, that regulate both side ends of the stacked envelope in a perpendicular direction to the conveyance direction, an attachment, removably mounted on the stacking unit, that regulates a trailing end of the stacked envelope, an operation unit that accepts a type of envelope via an instruction by a user, and a controller that determines, based on the type of the accepted envelope, whether the attachment is necessary, and if it is determined that the attachment is necessary, displays information, on the operation unit, for prompting the user to mount the attachment.

An image forming apparatus includes a correcting portion to correct gradation of inputted image data on the basis of a correction condition, an image forming device to form, on a recording material, a toner image corresponding to the corrected image data, a mounting portion, an executing portion to execute an output process for forming and outputting, on the recording material, a predetermined toner image for generating the correction condition, the predetermined toner image including a plurality of image regions different in density, an input portion to permit input of an execution instruction of the output process by an operator, and a controller to control notification of information to the operator. The controller provides notification prompting exchange of the fixing portions in certain cases.

There is provided a printing apparatus for conveying an envelope set in a paper feed unit and performing printing on the envelope and a method of controlling the printing apparatus. The printing apparatus determines whether or not attaching of an attachment to the paper feed unit is necessary in accordance with the type of envelope to be used, and, if it is determined that attaching of the attachment is necessary, the printing apparatus displays a message prompting attaching of the attachment.

An envelope processing apparatus inserts an enclosure into an envelope and includes a first conveyor, a first ejector, a second conveyor, a second ejector, and circuitry. The first conveyor conveys the enclosure to an enclosing position. The envelope in which the enclosure is enclosed is ejected to the first ejector. The second conveyor conveys the envelope to the enclosing position via an envelope conveyance passage extended in a substantially vertical and up-and-down direction and conveys the envelope in which the enclosure is inserted to the first ejector. The second ejector is separate from the first ejector. The enclosure is ejected to the second ejector. The circuitry controls a conveyance operation of the first conveyor and the second conveyor.

An image forming apparatus includes a gradation correcting portion, an image forming device, a toner image fixing device, a fixing device mounting portion, a detector, and an executing portion configured to execute a calibration process for generating a gradation correction condition on the basis of a result of detection of a predetermined toner image by the detector. The predetermined toner image is a toner image which is formed, on the basis of predetermined data, on the recording material by the image forming device and which is fixed by the fixing device mounted in the mounting portion, and the predetermined toner image forms a plurality of image regions different in density. The executing portion permits execution of the calibration process when the fixing device is the first fixing device, and prohibits the execution of the calibration process when the fixing device is the second fixing device.

A fixing device includes a hardness adjusting unit to adjust hardness of an outer circumferential surface of a fixing belt at a nip. When a sheet to be passed through the nip is an envelope, and the envelope is passed through the nip by side-flap sheet passing for feeding the sheet so that a fold line between an envelope body and a flap extends in a sheet passing direction through the nip, the hardness adjusting unit brings the outer circumferential surface of the fixing belt at the nip during passage of the sheet into a softer state than when the sheet is a plain sheet.

An image forming apparatus includes a fixing device that includes a pressing unit and a heating unit provided facing the pressing unit, an image-forming-apparatus body in which the fixing device is housed and to and from which the fixing device is attachable and detachable, a fixing-device-attachment-detachment-detecting member that detects attachment or detachment of the fixing device to or from the image-forming-apparatus body, and a controller that controls, if the fixing-device-attachment-detachment-detecting member detects the detachment of the fixing device from the image-forming-apparatus body, the image-forming-apparatus body to take a position where the pressing unit and the heating unit are to be pressed against each other.

A printing apparatus includes a holding unit configured to hold an envelope having a flap, a detection unit configured to detect a guide width between two guides provided in the holding unit, an acceptance unit configured to accept information about envelope size and flap length from a user, and a display control unit configured to determine whether to perform an error notification display based on the guide width detected by the detection unit as well as based on the envelope size and the flap length accepted by the acceptance unit.

Folding information and printing surface information, included in content information of a sealed letter creation job, are compared with content printing conditions stored in a storage section, and an appropriate condition (a conveyance path after printing, execution/non-execution of image rotation, and printing page order) is selected such that the position of a window of a windowed envelope is aligned with the position of specifying information printed on a print sheet P to be a content when the print sheet P is enclosed in the envelope. A convey section and a printing section are controlled based on the selected content printing condition.

An image forming device includes a toner image former forming, on a paper sheet, a toner image based on image information; a fixer including at least a pair of rollers and fixing the toner image by nipping, with a pressing member formed by the pair of rollers, the paper sheet on which the toner image is formed; an adjuster adjusting a pressure contact force applied by the pressing member to either a first pressure contact force or a second pressure contact force that is weaker than the first pressure contact force; and a controller controlling execution of a job related to image formation via the fixer, in which the controller provides a user with a notification that prompts the user to operate the adjuster for adjusting the pressure contact force to either the first pressure contact force or the second pressure contact force in accordance with the previously executed job.