An image forming device, including: a housing; a drawer movable between an inside position at which the drawer is located inside the housing and an outside position at which the drawer is located outside the housing; a drum cartridge including a photoconductive drum and a developer roller and mountable on the drawer; a toner cartridge storing toner to be supplied to the developer roller and mountable on the drawer, wherein the drawer includes a first guide that guides the toner cartridge in mounting the toner cartridge on the drawer, and wherein the drum cartridge includes a second guide connected to the first guide in a state in which the drum cartridge is mounted on the drawer, the second guide being configured to guide the toner cartridge in mounting the toner cartridge on the drawer in the state in which the drum cartridge is mounted on the drawer.

An image forming apparatus includes a unit horizontally insertable and drawable with respect to a main body frame, and a lock mechanism for the unit. The lock mechanism includes a lock member which has an engagement projection engageable with an engaged portion formed in the main body frame, and a biasing member which biases the lock member in a first direction toward engagement of the engagement projection with the engaged portion. Along with insertion of the unit, the lock member moves in a second direction, and when the unit is inserted to a predetermined position, biasing force of the biasing member causes the lock member to move in the first direction and the engagement projection engages with the engaged portion. By moving the lock member in the second direction, engagement between the engagement projection and the engaged portion is released to make it possible to draw the unit.

A sheet feeding device includes a sheet feeding cartridge, a pair of fixed rails, a pair of movable rails and a pressing part. The sheet feeding cartridge has a pair of side plates extending in taking-out/taking-in directions and is taken out/in an installed part in an apparatus main body. The fixed rails are extended in the taking-out/taking-in directions in the installed part. The movable rails are provided to move in the taking-out/taking-in directions along the fixed rails. If the pressing part is provided in one side plate, the pressing part applies biasing force to one movable rail facing to one side plate so that another side plate comes into pressure contact with another movable rail. If the pressing part is provided in one movable rail, the pressing part applies biasing force to one side plate so that another side plate comes into pressure contact with another movable rail.

An image forming apparatus includes a housing and a pair of cassette guides. The housing is provided with a cassette storage space and a unit storage space. The unit storage space is disposed above the cassette storage space and configured to slidably support an image forming unit. The housing has a pair of side plates arranged to be opposite to each other in a direction intersecting a sliding direction of the image forming unit. The pair of cassette guides is provided in the cassette storage space and arranged inside the pair of side plate. A guide rail part is formed by a gap between the side plate and the guide cassette arranged inside the side plate, and a top face of the cassette guide. A unit-side rail provided to the image forming unit is slidably engaged with the guide rail part.

An image forming device, including: a housing; a drawer movable between an inside position at which the drawer is located inside the housing and an outside position at which the drawer is located outside the housing; a drum cartridge including a photoconductive drum and a developer roller and mountable on the drawer; and a toner cartridge storing toner to be supplied to the developer roller and mountable on the drawer, wherein the drum cartridge and the toner cartridge are mountable on the drawer in a state in which the drawer is located at the outside position, and wherein the drum cartridge and the toner cartridge are arranged in a drawer moving direction in which the drawer moves, in the state in which the drum cartridge and the toner cartridge are mounted on the drawer.

A cartridge includes a projection portion provided in a first region of an upper surface of a frame in a vertical direction. The projection portion projects more upward than second regions between which the first region is interposed. An inside of the projection portion is a space that is part of a developer accommodating portion. The projection portion is configured to pass through a space under an abutting portion while being elastically deformed by the abutted portion being pressed by the abutting portion after the cartridge is transitioned from the first posture to the second posture in accordance with movement of the cartridge in the attaching direction.

A developer cartridge is described. The developer cartridge detachably mountable on a tandem type photosensitive unit slidable to a drawn-out position and a mounted position with respect to an image forming apparatus body may include a casing; a developer carrier rotatably supported on one end portion of the casing for carrying a developer; a pair of upright portions arranged on another end portion of the casing at an interval from each other in the axial direction of the developer carrier to extend from another end portion of the casing in a detaching direction for the developer cartridge; and an elastically deformable coupling portion extending in the axial direction of the developer carrier for coupling the upright portions with each other.

A developing cartridge may include: a casing to accommodate developer; a storage medium including an electric contact surface; an elastic member extending in a first direction crossing the electric contact surface, and configured to be compressed or stretched in the first direction between a first state and a second state; and a holder including an outer surface positioned toward a side of the holder in the first direction, the electric contact surface positioned at the outer surface, and movable between first and second positions in the first direction relative to the casing. A length of the elastic member in the first direction is greater in the first state than in the second state. The electric contact surface is in the first position when the elastic member is in the first state, and the electric contact surface is in the second position when the elastic member is in the second state.

When a position of a developing unit with respect to a photoreceptor unit, the developing unit being mounted in an image forming apparatus, is switched to a contact position from a separation position with a switching unit, the developing unit at the contact position is brought to a state forming a predetermined space with the guide unit through which an airflow generated by a fan and that flows in a longitudinal direction of the guide unit flows, and when the position of the developing unit with respect to the photoreceptor unit, the developing unit being mounted in the image forming apparatus, is switched to the separation position from the contact position with the switching unit, the developing unit at the separation position is brought to a state in which the developing unit enters at least a portion of an area of the predetermined space.

A damper mechanism has first and second rail members, a biasing member, and a slide member. The first rail member is fixed inside the opening/closing member along the up/down direction, and has an oblong guide hole formed therein extending along the longitudinal direction. The second rail member has fixed to a top end part thereof an engaging pin inserted through the guide hole, and has a bottom end part swingably supported on the apparatus main body. The biasing member biases the first and second rail members in a direction in which these approach each other. The slide member is made of resin fixed to the engaging pin, slides while in contact with the first rail member and the opening/closing member, and prevents contact between the engaging pin and an inner circumferential rim of the guide hole.