An image forming apparatus includes a main housing, a drawer, and a cartridge. The drawer is movable between an inside position inside the main housing and an outside position outside the main housing. The cartridge is installable into and removable from the drawer. The cartridge includes a photosensitive drum configured to rotate about a drum axis. The drawer comprises a lock member movable between a lock position in which the drawer is locked to the main housing, and an unlock position in which the drawer is unlocked from the main housing. The cartridge installed in the drawer is rotatable about the drum axis between a first position and a second position. The lock member is positioned in the lock position when the cartridge is positioned in the first position, and positioned in the unlock position when the cartridge is positioned in the second position.

An according to an aspect, a paper feed device includes a device body and a paper feed cassette inserted into the device body along an insertion direction. The paper feed device includes a lock lever mounted to the paper feed cassette via a lever shaft; a spring that applies a rotational force which rotates the lock lever in an engagement direction; and a lock member provided at the device body.

A medium transport device includes a transporting member, a medium offsetting member, a guide member, and an interlocking member. The guide member is located upstream of the transporting member in a medium transport direction. The guide member is movable between a first position, in which the guide member guides the medium toward the medium accommodating member, and a second position, in which the guide member guides the medium to a destination different from the medium accommodating member, to guide the medium. The interlocking member moves the guide member between the first position and the second position in conjunction with a movement of the medium offsetting member in a width direction of the medium offsetting member.

A medium transport device includes a transporting member, a medium offsetting member, a guide member, and an interlocking member. The transporting member transports a medium toward a medium accommodating member. The medium offsetting member moves the transporting member in a medium width direction to transport the medium to the medium accommodating member at positions shifted in the medium width direction. The guide member is located upstream of the transporting member in a medium transport direction. The guide member is movable between a first position, in which the guide member guides the medium toward the medium accommodating member, and a second position, in which the guide member guides the medium to a destination different from the medium accommodating member, to guide the medium. The interlocking member moves the guide member between the first position and the second position in conjunction with a movement of the medium offsetting member in a width direction of the medium offsetting member.

A locking mechanism includes a hook, an engaged portion, and a biasing member, and locks a movable unit supported on a unit main body to the unit main body. The hook has a supporting portion pivotably supported on the unit main body and an engaging portion protruding from the supporting portion. The engaged portion is formed on the movable unit and is engageable with the engaging portion. A biasing member biases the hook in such a direction as to let the engaging and engaged portions engage. The hook has a first face facing the engaged portion at the tip end of the engaging portion and a second face extending from the first face toward the supporting portion and inclined relative to the first face in such a direction as to recede from the pivot. With the engaging and engaged portion in engagement, the engaged portion touches only the second face.

A process cartridge includes: a drum cartridge; and a developing cartridge. The drum cartridge includes: a drum frame; a photosensitive drum rotatable about a first axis extending in a first direction; and a first memory having a first electrical contact surface. The developing cartridge is attachable to the drum frame and includes: a casing; a developing roller rotatable about a second axis extending in the first direction; a second memory having a second electrical contact surface; and a developing holder holding the second electrical contact surface such that the second electrical contact surface is movable relative to the casing. The drum cartridge further includes an elastic member that can expand and contract in a second direction crossing the first direction. The developing holder is connected to the elastic member and is movable in the second direction in a state where the developing cartridge is attached to the drum frame.

A locking mechanism includes a hook, an engaged portion, and a biasing member, and locks a movable unit supported on a unit main body to the unit main body. The hook has a supporting portion pivotably supported on the unit main body and an engaging portion protruding from the supporting portion. The engaged portion is formed on the movable unit and is engageable with the engaging portion. A biasing member biases the hook in such a direction as to let the engaging and engaged portions engage. The hook has a first face facing the engaged portion at the tip end of the engaging portion and a second face extending from the first face toward the supporting portion and inclined relative to the first face in such a direction as to recede from the pivot. With the engaging and engaged portion in engagement, the engaged portion touches only the second face.

An according to an aspect, a paper feed device includes a device body and a paper feed cassette inserted into the device body along an insertion direction. The paper feed device includes a lock lever mounted to the paper feed cassette via a lever shaft; a spring that applies a rotational force which rotates the lock lever in an engagement direction; and a lock member provided at the device body.

An image forming apparatus includes a main housing, a drawer, and a cartridge. The drawer is movable between an inside position inside the main housing and an outside position outside the main housing. The cartridge is installable into and removable from the drawer. The cartridge includes a photosensitive drum configured to rotate about a drum axis. The drawer comprises a lock member movable between a lock position in which the drawer is locked to the main housing, and an unlock position in which the drawer is unlocked from the main housing. The cartridge installed in the drawer is rotatable about the drum axis between a first position and a second position. The lock member is positioned in the lock position when the cartridge is positioned in the first position, and positioned in the unlock position when the cartridge is positioned in the second position.

An image forming apparatus includes a main housing, a drawer, and a cartridge. The drawer is movable between an inside position inside the main housing and an outside position outside the main housing. The cartridge is installable into and removable from the drawer. The cartridge includes a photosensitive drum configured to rotate about a drum axis. The drawer comprises a lock member movable between a lock position in which the drawer is locked to the main housing, and an unlock position in which the drawer is unlocked from the main housing. The cartridge installed in the drawer is rotatable about the drum axis between a first position and a second position. The lock member is positioned in the lock position when the cartridge is positioned in the first position, and positioned in the unlock position when the cartridge is positioned in the second position.