A high-voltage electrical circuit board is located in a first region that is a region at one side of photosensitive drums in a first direction and outside of the photosensitive drums in the first direction. A first motor drives a conveyance mechanism. A second motor is located in a second region and drives each photosensitive drum. A third motor is located in the second region and drives each developing roller to rotate and to drive a separation mechanism configured to individually move the developing rollers between a contact position and a separation position. A control board is located in the second region. The control board includes a controller configured to control a first applying circuit, the first motor, the second motor, and the third motor. The first motor, the second motor, the third motor, and the control board are located at different positions from one another in the second region.

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.

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 positon 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 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.

An image forming apparatus includes the following: an image forming portion; a first metal side plate and a second metal side plate provided opposite each other with respect to the image forming portion; an antenna for communicating with external equipment; a housing including a top cover that is provided above the first metal side plate and the second metal side plate in a vertical direction, and a side cover that is provided on an outer side opposite to an inner side where the image forming portion is provided with respect to the first metal side plate, wherein the image forming apparatus further includes a support member provided on the first metal side plate, the support member including a housing support portion that supports at least one of the top cover and the side cover, and an antenna support portion that supports the antenna.

An image forming apparatus including a photoreceptor unit, a first terminal, a stage, a first protrusion, a second protrusion, a slider, and an exposure device. The stage moves from a first position closer to the photoreceptor to a second position farther from the photoreceptor in a second direction than the first position so that the second terminal is fitted to the first terminal. The slider includes a first position regulation portion and a second position regulation portion at positions separated from each other in the third direction. A thickness of the first position regulation portion in the first direction is thinner than a thickness of the second position regulation portion in the first direction. The slider slides with the first protrusion between a base portion and the second protrusion and includes a guide portion. The exposure device is supported by the stage.

An image forming apparatus including a photoreceptor unit, a first terminal, a stage, a first protrusion, a second protrusion, a slider, and an exposure device. The stage moves from a first position closer to the photoreceptor to a second position farther from the photoreceptor in a second direction than the first position so that the second terminal is fitted to the first terminal. The slider includes a first position regulation portion and a second position regulation portion at positions separated from each other in the third direction. A thickness of the first position regulation portion in the first direction is thinner than a thickness of the second position regulation portion in the first direction. The slider slides with the first protrusion between a base portion and the second protrusion and includes a guide portion. The exposure device is supported by the stage.

A sheet conveyor device is to be attachably and detachably mounted to an external apparatus which forms an image on a sheet. The sheet conveyor device includes a judgement section, a speed determining section, and a conveyance controller. The judgement section determines which of a plurality of model groups the external apparatus belongs to based on specification information indicating specifications of the external apparatus. The speed determining section determines a conveyance speed at which the sheet is to be conveyed based on the determined model group. The conveyance controller directs conveyance of the sheet at the determined conveyance speed.

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.

A high-voltage electrical circuit board is located in a first region that is a region at one side of photosensitive drums in a first direction and outside of the photosensitive drums in the first direction. A first motor drives a conveyance mechanism. A second motor is located in a second region and drives each photosensitive drum. A third motor is located in the second region and drives each developing roller to rotate and to drive a separation mechanism configured to individually move the developing rollers between a contact position and a separation position. A control board is located in the second region. The control board includes a controller configured to control a first applying circuit, the first motor, the second motor, and the third motor. The first motor, the second motor, the third motor, and the control board are located at different positions from one another in the second region.