A belt feeding device includes a belt, a first roller, an opposing roller, a second roller, and a brush roller. (|D2sD2m|/2)10(|D2sD2m|/2)(b/(a+b)) is satisfied, where D2m is a minimum diameter of the first roller, D2s is a maximum diameter of the first roller, is an entering amount of the opposing roller into the brush roller with respect to a reference line A between a portion of the first roller having the minimum diameter D2m and the second roller, a is a distance between a line passing through a rotation center of the first roller and a line passing through a rotation center of the opposing roller, and b is a distance between a line passing through a rotation center of the second roller and a line passing through the rotation center of the opposing roller.

An image forming apparatus includes an image forming unit and a developing separation mechanism. The image forming unit includes an image carrier and a developing device. The developing device includes a developing member and movable in a developing position where the developing member is in contact with the image carrier and a separated position where the developing member is separated away from the image carrier, and is configured to be drawn out from an apparatus main body. The developing separation mechanism includes an arm member configured to interfere with the developing device from a downstream side of a draw-out direction so as to move the developing device from the developing position to the separated position, and to be turned to an upstream side of the draw-out direction by the image forming unit when the image forming unit is drawn out and then be separated from the developing device.

A sheet transport device includes a first transport route, a roller, a second transport route, a switching nail, a lever, a sheet detection piece, a cam, an intermediate rotary member, a rotary member, a sensor, a driver, and a controller. The controller controls the driver to switch the switching nail between a first transport position and a second transport position, decides that the sheet is transported through first transport route, when the sheet detection piece retreats contacted by the sheet on the first transport route, with the switching nail being set to the first transport position, and the sensor detects that the rotary member is in the second posture, and decides that the switching nail has been switched from the first transport position to the second transport position, when the sensor detects that the rotary member is in the second posture, after the sheet has passed the sheet detection piece.

An image forming device includes: a conveyance path that conveys a printing medium; an image former that is arranged in a first place in the middle of the conveyance path, forms an image on one surface of the printing medium, and fixes the formed image by heating; a cooler that is arranged in a second place downstream in a conveyance direction from the first place in the middle of the conveyance path, and cools the printing medium by blowing air for cooling to the printing medium; and a reader that is arranged in a third place downstream in the conveyance direction from the second place in the middle of the conveyance path, and reads the image formed on the printing medium, wherein between the first place and the second place of the conveyance path, one or a plurality of guide members is provided, and a guide member is not provided.

An image forming apparatus includes a first side plate, a second side plate, a first connecting member, the first connecting member being secured to the first side plate at a first securing portion and being secured to the second side plate at a second securing portion, and a frame, the frame being sandwiched between the first side plate and the second side plate and being secured to the first side plate and the second side plate. At least one of the first side plate and the first connecting member is deformed to form the first securing portion, and at least one of the second side plate and the first connecting member is deformed to form the second securing portion.

A transport device includes a transporting roller that includes a first shaft portion, a first roller configured to have plural cylindrical first roller portions into which the first shaft portion is inserted and which are separated from each other in an axial direction of the first shaft portion, and a second roller coming into contact with the first roller and extends in a direction of the first shaft portion, and that transports a recording medium; and a guide member that is disposed on a first roller side with respect to a transport path of the recording medium and that is formed with a guide surface guiding the recording medium toward the transporting roller while changing a transport direction of the recording medium to be transported, the guide surface of a separation portion which is separated from the first roller in the axial direction extending to a downstream side in the transport direction as compared with the guide surface of an overlapping portion which overlaps the first roller in the axial direction.

An example image forming apparatus includes a printing portion to print an image on a print medium, a gate member at an outgoing side of the printing portion to selectively guide the print medium discharged from the printing portion to a first route or a second route, and a reading member in the first route to read the image from the print medium discharged from the printing portion.

An image forming apparatus includes a first side plate, a second side plate, a first connecting member, the first connecting member being secured to the first side plate at a first securing portion and being secured to the second side plate at a second securing portion, and a frame, the frame being sandwiched between the first side plate and the second side plate and being secured to the first side plate and the second side plate. At least one of the first side plate and the first connecting member is deformed to form the first securing portion, and at least one of the second side plate and the first connecting member is deformed to form the second securing portion.