An image forming apparatus includes an image forming portion capable of forming a toner image on an envelope including a flap; a stacking portion configured to stack the envelope; a fixing portion configured to fix the toner image on the envelope; a display portion configured to display information; an acquiring portion configured to acquire information corresponding to a kind of the envelope; and a controller configured to control the display portion when a double-side mode is selected, so that a stacking method in which the envelope is stacked on the stacking portion in a state in which an orientation of the envelope is designated on the basis of the information acquired by the acquiring portion is displayed at the display portion.

An image forming apparatus includes an image forming portion capable of forming a toner image on an envelope including a flap; a stacking portion configured to stack the envelope; a fixing portion configured to fix the toner image on the envelope; a display portion configured to display information; and a controller configured to control the display portion so that when the double-side mode in which the images are formed on the double sides of the envelope is selected, a stacking method in which the envelope is stacked on the stacking portion so as to fix the image on a flap-formed side when the envelope first passes through the fixing portion is displayed at the display portion.

An image forming apparatus includes an image formation unit, an image heating unit, a placement unit, and a control unit. The image heating unit heats an image formed by image formation unit on the recording material that was placed on the placement unit. If an envelope is placed on the placement unit with a flap of the envelope in a direction perpendicular to a conveyance direction of a recording material, the control unit executed control to automatically execute two-sided printing on the envelope such that images formed on a first and a surface of the envelope are heated by the image heating unit. If an envelope is placed on the placement unit with a flap of the envelope in the conveyance direction of the recording material, the control unit executes control to inhibit execution of two-sided printing on the envelope.

An image forming apparatus includes an image formation unit, an image heating unit, a placement unit, and a control unit. The image heating unit heats an image formed by image formation unit on the recording material that was placed on the placement unit. If an envelope is placed on the placement unit with a flap of the envelope in a direction perpendicular to a conveyance direction of a recording material, the control unit executed control to automatically execute two-sided printing on the envelope such that images formed on a first and a surface of the envelope are heated by the image heating unit. If an envelope is placed on the placement unit with a flap of the envelope in the conveyance direction of the recording material, the control unit executes control to inhibit execution of two-sided printing on the envelope.

An enclosing device includes an envelope conveyance path, an envelope loader, an envelope-position restrictor, and an envelope-position adjuster. The envelope conveyance path conveys an envelope to an enclosing position at which an enclosure is enclosed into the envelope. The envelope loader loads the envelope to be supplied to the envelope conveyance path. The envelope-position restrictor restricts a loaded position of the envelope in the envelope loader. The envelope-position adjuster adjusts a position of the envelope with respect to a conveyance direction of the envelope while maintaining a state in which the envelope-position restrictor restricts the loaded position of the envelope.

A fixing device for an envelope includes an endless belt, a driving rotatable member, and a pad that includes a base portion, a first projecting portion projecting from the base portion toward the driving rotatable member at an upstream end in a feeding direction of the envelope, a second projecting portion projecting from the base portion toward the driving rotatable member at a downstream end in the feeding direction of the envelope, and a recess portion, provided between the first projecting portion and the second projecting portion in the feeding direction of the envelope. When a fixing process is performed on the envelope, an inner surface of the endless belt is in contact with both of the first projecting portion and the second projecting portion, and is spaced from the recess portion.

A recording material discriminating apparatus includes: a hardware processor that: detects a physical property of a recording material in different ways; and when transmittance of the recording material is within a first range, discriminates a type of the recording material by using a detection result from the hardware processor, and when the transmittance of the recording material is within a second range different from the first range, discriminates the type of the recording material by using a detection result from the hardware processor.

An image forming apparatus includes a correcting portion, an image forming device, and a fixing device that is one of a first fixing device including a first pair of rotatable members forming a first nip under a first load, and a second fixing device including a second pair of rotatable members forming a second nip under a second load that is less than the first load. A mounting portion selectively mounts one of the plurality of fixing devices. A detector detects a density of a toner image fixed on a recording material. When the fixing device is the first fixing device, an executing portion permits execution of a calibration process for generating a correction condition on the basis of a result of detection of a predetermined toner image by the detector, and, when the fixing device is the second fixing device, the executing portion prohibits execution of the calibration process.

An image forming apparatus includes a reading configured to read a shape of a sheet to be used for image formation, and an original sheet carrying an original image, and an image forming portion configured to form a toner image, corresponding to the original image read by the reading portion, on the sheet to be used for image formation. A fixing portion is configured to fix the toner image, formed by the image forming portion, to the sheet to be used for image formation. In addition, a controller is configured to control a fixing condition of the fixing portion in accordance with the shape of the sheet to be used for image formation read by the reading portion.

A press-bonded sheet in which two sheet portions are press-bonded in a peelable state is manufactured by a method including steps of: forming an adhesive layer containing powder adhesive on a sheet; heating the adhesive layer to fix it to the sheet; opposing an area on the sheet where the adhesive layer is fixed and an area on the same sheet or on a different sheet where another adhesive layer is formed and fixed; and press-bonding the opposed areas. The fracture strain of a main constituent material of the powder adhesive is 10% or more and less than 1000%.