Abstract: An image forming apparatus includes: a main body; a photosensitive drum rotatably supported in the main body; a developing unit detachably accommodated in the main body in a direction along an axis of the photosensitive drum in a state where the photosensitive drum is disposed in the main body. The developing unit includes: a developer carrying member configured to carry developer for supplying the developer to the photosensitive drum; a developing frame supporting the developer carrying member; and a supporting assembly configured to support the developing frame such that, in a state where the developing unit is accommodated in the main body, the developing frame is movable between a proximity position where the developer carrying member and the photosensitive drum being positioned adjacent to or in contact with each other and a separation position where the developer carrying member and the photosensitive drum being separated from each other.

Abstract: An image forming device includes a main body having a metal main frame, first and second resin frames attached to the main frame, a conveying section attached to the first resin frame and made of third resin, an input section provided to the conveying section, and an output section supported to the second resin frame and liked to the input section. The conveying section conveys a recording medium upon receiving driving force through the input section and the output section. Both the first and second resin frames have a higher liner expansion coefficient than the main frame, and a linear expansion coefficient of the third resin is higher than that of the main frame and lower than that of the first and second resin frames.

Abstract: An image forming apparatus includes a first right frame, a first left frame facing the first right frame, a second right frame positioned below the first right frame, a second left frame facing the second right frame and positioned below the second right frame. The image forming apparatus further includes an image forming unit positioned between the first right frame and the first left frame. The image forming apparatus still further includes a frame connecting unit configured to connect the first right frame, the first left frame, the second right frame and the second left frame. The first right frame and the second right frame are relatively slidable in an up-down direction, and the first left frame and the second left frame are relatively slidable in the up-down direction.

Abstract: There is provided an image forming apparatus includes an apparatus body having an opening, an open/close member which opens and closes the opening, and an image forming unit which is drawable to an outside of the apparatus body through the opening. The open/close member includes a restraint member which is movable between a restraint position of restraining movement of the image forming unit and a restraint release position of releasing the restraint, and a moving member which moves the restraint member from the restraint position toward the restraint release position as the open/close member being moved from a close position to an open position. Once the restraint member is moved from the restraint position toward the restraint release position, the restraint member is held at the restraint release position not to be moved from the restraint release position to the restraint position even when the open/close member is moved.

Abstract: An electrode for an image forming apparatus, the electrode including: an elastically deformable spring portion that is formed in a cylindrical shape by spirally winding a wire; a ring portion that is an electrical contact portion having an annular shape and provided to one end side of the spring portion in an axial direction of the spring portion, the ring portion being formed by winding the wire around a center line, which intersects with the axial direction of the spring portion, at least twice; an inner portion that is formed by the wire forming the ring portion and is positioned at an inside of the ring portion; and an outer portion that is formed by the wire forming the ring portion and is positioned at an outside of the ring portion.

Abstract: A photosensitive drum extends in an axial direction. An irradiating unit includes a first reacting portion and a second reacting portion spaced from each other in the axial direction. A moving member includes a first acting portion and a second acting portion spaced from each other in the axial direction. The first acting portion and the second of the moving member act on the first reacting portion and the second reacting respectively, in response to attachment of the developing unit to a main body, such that the irradiating unit moves from the retracted position to the proximate position with respect to the photosensitive drum, and cancel the actions on the first reacting portion and the second reacting portion respectively, in response to removal of the developing unit from the main body, such that the irradiating unit moves from the proximate position to the retracted position.

Abstract: An image forming apparatus includes a plurality of photosensitive drums, a frame member, a first sheet metal member, and a pressing member. The frame member is configured to accommodate the photosensitive drums such that the photosensitive drums are withdrawn along an axial direction thereof. The first sheet metal member is disposed on a first side of the frame member and configured to position the photosensitive drums. The pressing member is configured to press the photosensitive drums toward the first sheet metal member. The frame member includes a first wall disposed on a second side, opposite to the first side, of the frame member in the axial direction, a second wall disposed on a third side of the frame member and connected to the first wall, and a third wall disposed on an upper side relative to the photosensitive drums and connected to the first wall and the second wall.

Abstract: A photosensitive drum is rotatably supported in a main body. A developing cartridge is detachably mountable on the main body in a state where the photosensitive drum is supported in the main body. The developing cartridge includes a developing device and a frame. The developing device includes a developing roller disposed in confrontation with the photosensitive drum to supply developer to the photosensitive drum when the developing cartridge is mounted in the main body, and a developer-accommodating portion configured to accommodate developer. The frame includes a waste-developer-accommodating portion configured to accommodate waste developer and supports the developing device that is movable relative to the frame. The frame is disposed on an opposite side of the developing roller from the photosensitive drum. An urging member is disposed between the frame and the developing device to urge the developing roller toward the photosensitive drum.

Abstract: A fixing device for fixing a developed image of developer onto a recording sheet by heating and fusing the developer includes a heating roller, a pressure roller and a driving force input element. The heating roller is configured to be heated by a heat source, such as a halogen heater. The pressure roller is disposed adjacent to the heating roller, such that a recording sheet is fed and conveyed between the pressure roller and the heating roller. The driving force input element is fixed to the pressure roller for causing the pressure roller to rotate. A diameter Dp of the pressure roller and a nip width N between the heating roller and the pressure roller in circumferential directions thereof have a relationship represented by the following expression: 0.24<N/Dp<0.6.

Abstract: An image forming apparatus including: a frame member including a first electrode and a replacement unit including a second electrode that electrically contacts the first electrode. The replacement unit is movable relative to the frame member along a moving direction. The moving direction includes a first direction and a second direction that intersects the first direction. The first electrode is formed by a wire and includes a contact portion. The contact portion, which is bent along an intersection plane, is movable in a third direction that is perpendicular to the first direction and the second direction. A direction of the contact portion is set so that the intersection plane intersects with a first plane and a second plane at angles smaller than an intersection angle formed by the intersection of the first plane and the second plane.

Abstract: An electrophotographic image forming apparatus may include a main body including a reference protrusion having a reference surface on one side and a pressing member on the other side, and a photosensitive member unit configured to move between an operational position and an outer position. The photosensitive member unit stops at a particular position located between the outer position and the operational position. The reference surface of the main body may contact the photosensitive member unit located in the operational position. The pressing device of the main body may be configured to press the photosensitive member unit toward the reference surface when the photosensitive member unit is located in the particular position and in the operational position.

Abstract: An image forming device includes a permitting unit and a moving unit. The permitting unit selectively establishes a first positional relationship in which photosensitive members contact an endless belt and a second positional relationship in which the photosensitive members separate from the endless belt. The moving unit moves a charger between a first position confronting the corresponding photosensitive member at a rear side thereof in a juxtaposed direction and a second position moved away from the first position. The endless belt confronts the photosensitive members at a top side thereof in an orthogonal direction. Each developer cartridge confronts the corresponding photosensitive member at a bottom side thereof. The developer cartridge is attachable to and detachable from a main casing while moved past a front side of the corresponding photosensitive member when the second positional relationship is established and the neighboring charger is in the second position.

Abstract: An image forming apparatus includes a main frame and a holder. The holder holds a plurality of photosensitive drums arrayed in a predetermined direction. The holder includes a pair of side plates each positioned at each axial end portion of each photosensitive drum, and each having an upstream end portion in the accommodating direction, and a pair of protruding portions each protruding outward in the axial direction from the upstream end portion of each side plate. The main frame includes a pair of positioning portions and a pair of support portions. The pair of positioning portions is configured to be in contact with each protruding portion from below and downstream side of the protruding portion in the accommodating direction. The pair of support portions is positioned downstream of the pair of positioning portions in the accommodating direction and configured to support the pair of side plates.

Abstract: A fixing device for fixing a developed image of developer onto a recording sheet by heating and fusing the developer includes a heating roller, a pressure roller and a driving force input element. The heating roller is configured to be heated by a heat source, such as a halogen heater. The pressure roller is disposed adjacent to the heating roller, such that a recording sheet is fed and conveyed between the pressure roller and the heating roller. The driving force input element is fixed to the pressure roller for causing the pressure roller to rotate. A diameter Dp of the pressure roller and a nip width N between the heating roller and the pressure roller in circumferential directions thereof have a relationship represented by the following expression: 0.24<N/Dp<0.6.

Abstract: There is provided a thermal fixing unit that fixes a toner image on a printing medium, the fixing unit including a heat member, a pressure pad, a movable supporting assembly, and an urging member. The heat member is in contact with the printing medium, being positionally fixed and defining an axis. The pressure pad is disposed in opposition to the heat member for nipping the printing medium in cooperation with the heat member. The supporting assembly pivotably movably supports the pressure pad. The urging member biases the supporting assembly to urge the pressure pad toward the heat member for providing pressure contact between the heat member and the pressure pad.

Abstract: An image forming apparatus includes a pressure unit and first and second positioning portions. A photosensitive unit, configured to be mounted in a main frame of the image forming apparatus along a prescribed direction, may include a plurality of photosensitive drums, a pair of metal plates, and a resin frame. The pair of metal plates is spaced away from each other in the axial direction of each photosensitive drum and supports the photosensitive drums. The metal plates are configured to be positioned on the second positioning portion. The resin frame is configured to support the metal plates and developer cartridges. The resin frame is further configured to be positioned on the first positioning portion. The pair of metal plates is pressed against the second positioning portion to be positioned with respect to the main frame when the resin frame is pressed by the pressure unit in the prescribed direction.

Abstract: An image forming apparatus includes a casing, a photosensitive member, a developing unit, an exposure member including a light emitting element array, a covering member, and a cover operation mechanism. The developing unit includes a developer carrying member configured to carry a developer supplied to the photosensitive member. The exposure unit is configured to expose the photosensitive member to form a latent image on the photosensitive member. The covering member is configured to move between a cover position where the covering member covers the exposure member between the photosensitive member and the exposure member and a retracted position where the covering member is retracted from between the photosensitive member and the exposure member. The cover operation mechanism is configured to hold the covering member in the retracted position at least when the exposure member forms the latent image on the photosensitive member.

Abstract: An image forming apparatus includes a casing, photosensitive members arranged along an arrangement direction, and developing cartridges. Each developing cartridge includes a developer carrying member configured to supply a developer to a corresponding one of the photosensitive members. Each photosensitive member is configured to move between an image formation position where an image is formed on the photosensitive member and a retracted position where the photosensitive member is retracted from the developer carrying member. When the photosensitive member is in the image formation position, the photosensitive member is configured to close a path through which a corresponding one of the developing cartridges is attached to and removed from the casing. When the photosensitive member is in the retracted position, the photosensitive member is configured to open the path.

Abstract: An image forming apparatus is provided which includes an image forming unit, a main body having a pair of frames, a pair of rollers, a belt which is endless, and a reinforcing member. The frames are disposed to sandwich the image forming unit therebetween. The rollers are spaced apart from each other such that an axial direction of each of the rollers extends in a direction perpendicular to the frames. The belt extends around the rollers. The reinforcing member is disposed in an area enclosed by the belt. One end of the reinforcing member is fixed to one of the frames, and the other end of the reinforcing member is fixed to the other one of the frames.

Abstract: An image forming apparatus includes: upper frames opposed to each other across an image forming unit; a scanner supporting member that couples the upper frames and supports the scanner unit; and a frame coupling member that couples the upper frames on an opposite side of the scanner supporting member across the photoconductor unit; lower frames, each of which has an upper surface including a plurality of lower supporting portions each contacting a lower end of a respective one of the upper frames, and a lower surface including a bottom supported portion opposed to a placing surface. A stiffness of each of the upper frames in a substantially planar direction along the vertical direction is greater than a stiffness of each of the lower frames along the vertical direction between the lower supporting portions and the bottom supported portion.