A drawer is moveable between an inner position and an outer position through an opening when a cover is located at an opening position. A waste toner conveying tube is movable in a second direction between a first connection position and a first disconnection position when a drum cartridge is attached to a drawer and the drawer is at the inner position. When the cover moves from a closing position toward the opening position, the waste toner conveying tube moves from the first connection position toward the first disconnection position in conjunction with the movement of the cover. The drawer is movable from the inner position toward to the outer position when the drum cartridge is attached to the drawer, the drawer is at the inner position, and the waste toner conveying tube is at the first disconnection position.

An image forming apparatus including a main body casing, a cover, a drum cartridge, a developing cartridge, an intermediate transfer belt and a movable cam. The movable cam is movable among a first position when the cover is in the open position, a second position and a third position when the cover is in the closed position. In a case where the movable cam is in the first position, the photosensitive drum is in a first drum position spaced from the intermediate transfer belt, and the developing roller is in a first developing position spaced from the photosensitive drum. In a case where the movable cam is in the second position, the photosensitive drum is positioned toward the intermediate transfer belt from the first drum position. In a case where the cam is in the third position, the developing roller is positioned toward the photosensitive drum from the first developing position.

A container attachment device includes a toner container, an attached part for the toner container and a displacement sensor. The displacement sensor faces to the toner container to detect electrostatic capacity according to the toner. The attached part includes a cover opening/closing an opening of the toner container. The cover closing or opening the opening faces to the displacement sensor, and the cover opening or closing the opening is away from the displacement sensor. The displacement sensor detects the electrostatic capacity varying among a first condition opening the cover and detaching the toner container, a second condition closing the cover and detaching the toner container, a third condition opening the cover and attaching the toner container, and a fourth condition closing the cover and attaching the toner container. In the third or fourth condition, the displacement sensor detects the electrostatic capacity according to a toner quantity in the toner container.

A metal frame of an image forming apparatus including an image forming unit which forms an image on a sheet includes: a first support member which is a sheet plate supporting the image forming unit and has a slit portion formed therein, the slit portion being a through-hole; a second support member which is arranged with an interval from the first support member and supports the image forming unit together with the first support member; and a beam member which is a sheet metal connecting the first support member and the second support member to each other, wherein the beam member includes: a facing portion which faces a first region of the first support member around the slit portion; and a fitted portion which is supported by an inner peripheral end surface of the slit portion and is fitted into the slit portion in a plate thickness direction of the fitted portion, wherein a width of the fitted portion in a direction vertical to a plate thickness direction of the first support member and the plate thickness direction of the fitted portion in the slit portion is less than or equal to a width of the slit portion in the vertical direction, and wherein the fitted portion includes a hook portion which is provided on a rear surface of a surface of the first support member on which the first region is provided, includes an end surface of the beam member facing a second region of the first support member adjacent to the slit portion in the vertical direction, with a gap, and has a hook shape.

An image forming apparatus includes a main assembly including a main assembly frame and an image forming portion; a reading unit including a reading frame, a placing portion, a reading portion, and a hinge supporting portion; a hinge; and an openable unit. The hinge supporting portion includes a first fixing portion fixed to the reading frame and a second fixing portion provided adjacent to the main assembly frame and fixed to the main assembly frame.

An image forming apparatus includes a main assembly including a main assembly frame and an image forming portion; a reading unit including a reading frame, a placing portion, a reading portion, and a hinge supporting portion; a hinge; and an openable unit. The hinge supporting portion includes a first fixing portion fixed to the reading frame and a second fixing portion provided adjacent to the main assembly frame and fixed to the main assembly frame.

An image forming apparatus includes an apparatus main body to which a cartridge is detachably attached. The apparatus main body includes a frame having an opening portion through which the cartridge is attached to the apparatus main body; an opening and closing member supported by the frame rotatably between an open position in which the opening portion is exposed and a closed position in which the opening portion is covered with the opening and closing member and having a stacking surface on which a sheet is to be stacked; a discharging roller discharging the sheet in a discharging direction onto the stacking surface; and a regulating wall which is movably attached to the opening and closing member and extends from the stacking surface toward the discharging roller in a direction intersecting the discharging direction to regulate an upstream edge of the sheet in the discharging direction.

An accessory mating system for mating a print engine to an accessory may include a pin and a pin receiving detent. The pin has a collar having a pin vertical axis datum surface and a shaft extending from the collar. The shaft provides left-right axis datum surfaces and second opposite sides providing fore-aft axis datum surfaces. The pin receiving detent receives the pin. The pin receiving detent may include a detent perimeter providing a detent vertical axis datum surface, first opposite internal sides providing first detent left-right axis datum surfaces facing the pin left-right axis datum surfaces and second opposite internal sides providing detent fore-aft axis datum surfaces.

A developing cartridge includes: a casing; a developing roller; a shaft extending in a first direction; a first inclined surface; a second inclined surface; an elastic member; and a first protrusion. The shaft is movable in the first direction relative to the casing and the developing roller, and is movable in the second direction together with the same. The first inclined surface is positioned at one end portion of the shaft, while the second inclined surface is positioned at another end portion of the shaft. The first and second inclined surfaces are inclined relative to the first direction. The first protrusion is movable in the first direction together with the second inclined surface. The shaft is movable from a first position to a second position when the second inclined surface receives a pressing force directed in a direction from the another end portion to the one end portion.

An image forming apparatus, having a casing, a drum unit including first and second lateral walls and first and second photosensitive drums, first and second cartridges supported by the drum unit, first and second operable members, is provided. The first operable member and the second operable member press the first developing cartridge and the second developing cartridge, respectively, in a direction from the first lateral wall toward the second lateral wall to move the first and second developing rollers from the respective contacting positions to respective separated positions. The casing includes a restrictive portion. When the drum unit is attached to the casing, the restrictive portion restricts movement of the drum unit erasable by at least one of a pressing action of the first operable member to press the first developing cartridge and a pressing action of the second operable member to press the second developing cartridge.