Abstract: An image forming apparatus is provided for forming an image on a recording material. An opening is provided to a main assembly of the image forming apparatus, with first and second openable members being movable between closed positions in which portions of the opening are closed and open positions in which portions of the opening are opened. A movable member is movable between a set position inside the main assembly and an outward position in which the movable member, having passed through the opening, is located at an outermost position. The movable member is capable of supporting a plurality of cartridges, side by side, with each of the cartridges including at least one of an image bearing member on which a latent image is to be formed and a developing roller for developing with a developer the latent image formed on the image bearing member.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. The image forming apparatus of the present invention prevents a friction force between the belt and the transfer device rubbing the belt from increasing and brings a transfer member into a stable contact with the belt for conveying the toner image, thereby suppressing increase in drive torque of the belt which rubs the transfer device and suppressing occurrence of image failure.

Abstract: An image forming apparatus is provided for forming an image on a recording material. An opening is provided to a main assembly of the image forming apparatus, with first and second openable members being movable between closed positions in which portions of the opening are closed and open positions in which portions of the opening are opened. A movable member is movable between a set position inside the main assembly and an outward position in which the movable member, having passed through the opening, is located at an outermost position. The movable member is capable of supporting a plurality of cartridges, side by side, with each of the cartridges including at least one of an image bearing member on which a latent image is to be formed and developing means for developing with a developer the latent image formed on the image bearing member.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. The image forming apparatus of the present invention prevents a friction force between the belt and the transfer device rubbing the belt from increasing and brings a transfer member into a stable contact with the belt for conveying the toner image, thereby suppressing increase in drive torque of the belt which rubs the transfer device and suppressing occurrence of image failure.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. The image forming apparatus of the present invention prevents a friction force between the belt and the transfer device rubbing the belt from increasing and brings a transfer member into a stable contact with the belt for conveying the toner image, thereby suppressing increase in drive torque of the belt which rubs the transfer device and suppressing occurrence of image failure.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. The image forming apparatus of the present invention prevents a friction force between the belt and the transfer device rubbing the belt from increasing and brings a transfer member into a stable contact with the belt for conveying the toner image, thereby suppressing increase in drive torque of the belt which rubs the transfer device and suppressing occurrence of image failure.

Abstract: An image forming apparatus for forming an image on a recording material includes an opening provided to a main assembly of the apparatus, a first openable member, a second openable member, and a movable member. The movable member is movable between a set position inside the main assembly and an outward position. The first openable member can be located at an open position below the movable member located at the outward position. An outermost end of the movable member can be located at the outward position so as to be vertically aligned with or located inside an outermost end of the first openable member located at the open position.

Abstract: An image forming apparatus for forming image on a recording medium includes a photosensitive member, a motor, a belt, and a drive member to rotate the belt, the drive member including a driven coupling. The apparatus also includes a drive coupling to rotate by a driving force generated by the motor, the drive coupling being movable in an axial direction to take an engagement position at which the driving force is transmittable to the driven coupling, and a release position. The apparatus further includes a transfer member to transfer a toner image onto the recording medium or the belt, a voltage application unit to apply a voltage to the transfer member, and a control unit to cause the voltage application unit to apply the voltage to the transfer member after the drive coupling moves to the engagement position and the driving force is transmitted to the driven coupling.

Abstract: A color electrophotographic image forming apparatus in which a cartridge tray supporting a plurality of cartridges is movable through a plurality of opening portions to respective outside positions outside an apparatus main body. In the color electrophotographic image forming apparatus, the plurality of cartridges are removably mounted to the apparatus main body to form an image on a recording medium. The color electrophotographic image forming apparatus includes: a cartridge tray (26), which is movable, while supporting the plurality of cartridges, between an inside position positioned inside the apparatus main body and the outside positions; a plurality of opening portions (31, 92) provided in the apparatus main body, through which the cartridge tray (26) is movable between the inside position and the outside positions; and doors (28, 94) for opening and closing the plurality of opening portions (31, 92).

Abstract: An image forming apparatus for forming image on a recording medium includes a photosensitive member, a motor, a belt, and a drive member to rotate the belt, the drive member including a driven coupling. The apparatus also includes a drive coupling to rotate by a driving force generated by the motor, the drive coupling being movable in an axial direction to take an engagement position at which the driving force is transmittable to the driven coupling, and a release position. The apparatus further includes a transfer member to transfer a toner image onto the recording medium or the belt, a voltage application unit to apply a voltage to the transfer member, and a control unit to cause the voltage application unit to apply the voltage to the transfer member after the drive coupling moves to the engagement position and the driving force is transmitted to the driven coupling.

Abstract: An image forming apparatus for forming an image on a recording material includes an opening provided to a main assembly of the apparatus; a first openable member movable between a closed position in which a first portion of the opening is closed and an open position in which the first portion of the opening is opened; a second openable member movable between a closed position in which a second portion of the opening is closed and an open position in which the second portion of the opening is opened; and a movable member, movable between a set position inside the main assembly and an outward position in which the movable member having passed through the first portion of the opening is located at an outermost position in a movable range of the movable member, capable of supporting a plurality of cartridges, side by side, each including at least one of an image bearing member on which a latent image is to be formed and developing means for developing with a developer the latent image formed on the image bearing

Abstract: An image forming apparatus for forming image on a recording medium includes a photosensitive member, a motor, a belt, and a drive member to rotate the belt, the drive member including a driven coupling. The apparatus also includes a drive coupling to rotate by a driving force generated by the motor, the drive coupling being movable in an axial direction to take an engagement position at which the driving force is transmittable to the driven coupling, and a release position. The apparatus further includes a transfer member to transfer a toner image onto the recording medium or the belt, a voltage application unit to apply a voltage to the transfer member, and a control unit to cause the voltage application unit to apply the voltage to the transfer member after the drive coupling moves to the engagement position and the driving force is transmitted to the driven coupling.

Abstract: An image forming apparatus includes: an image bearing member for bearing a toner image; a belt for conveying the toner image; and a transfer device for rubbing the belt, and a surface of the transfer device, which is brought into contact with the belt includes linear concave portions or linear convex portions. The image forming apparatus of the present invention prevents a friction force between the belt and the transfer device rubbing the belt from increasing and brings a transfer member into a stable contact with the belt for conveying the toner image, thereby suppressing increase in drive torque of the belt which rubs the transfer device and suppressing occurrence of image failure.

Abstract: A process cartridge is detachably mountable to a main assembly of an electrophotographic image forming apparatus. The cartridge includes an electrophotographic photosensitive member, a cartridge positioning portion, engageable with the main assembly for positioning the cartridge relative to the main assembly, and a cartridge movable member movable by movement of a main assembly movable member, when the cartridge, upon mounting of the cartridge to the main assembly while guided by a main assembly guiding member, stops upstream, with respect to a cartridge mounting direction, of an image formation position where the cartridge positioning portion is engaged with the main assembly positioning portion, the cartridge movable member is moved by movement of a main assembly movable member to contact to the guiding member, by which the cartridge movable member receives, from the guiding member, a force for moving the process cartridge downstream with respect to the mounting direction.

Abstract: An electrophotographic photosensitive drum is for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The main assembly includes a motor, and a gear having a non-circular twisted hole. The drum includes a cylinder having a non-circular twisted projection engageable with the hole to receive a driving force from the main assembly when the cartridge is mounted to the main assembly. A recess is formed in the projection and has a bottom portion and a side surface portion. When the projection receives a pulling force toward the hole by rotation of the gear with the projection and the hole being engaged with each other, the bottom portion contacts a spherical surface portion provided at a central portion of the hole, and the side surface portion contacts the spherical surface portion.

Abstract: An image forming apparatus includes an image bearing member, wherein a toner image is formed on the image bearing member and is transferred onto a recording material, thus forming an image on the recording material; a shaft for rotating the image bearing member, wherein the shaft is provided with a first projection and a second projection, and the image bearing member is provided with a first engaging portion and a second engaging portion which are engageable with the first projection and the second projection, respectively, and wherein the first engaging portion is abuttable to the first projection at downstream and upstream sides of the first projection with respect to a rotational direction of the shaft, and the second engaging portion is abuttable to the second projection at a downstream side of the second projection, and wherein a gap is provided between the second engaging portion and the second projection at an upstream side of the second projection.

Abstract: An electrophotographic photosensitive drum is for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The main assembly includes a motor, and a gear having a non-circular twisted hole. The drum includes a cylinder having a non-circular twisted projection engageable with the hole to receive a driving force from the main assembly when the cartridge is mounted to the main assembly. A recess is formed in the projection and has a bottom portion and a side surface portion. When the projection receives a pulling force toward the hole by rotation of the gear with the projection and the hole being engaged with each other, the bottom portion contacts a spherical surface portion provided at a central portion of the hole, and the side surface portion contacts the spherical surface portion.

Abstract: An electrophotographic photosensitive drum is for a process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus. The main assembly includes a motor, and a gear having a non-circular twisted hole. The drum includes a cylinder having a non-circular twisted projection engageable with the hole to receive a driving force from the main assembly when the cartridge is mounted to the main assembly. A recess is formed in the projection and has a bottom portion and a side surface portion. When the projection receives a pulling force toward the hole by rotation of the gear with the projection and the hole being engaged with each other, the bottom portion contacts a spherical surface portion provided at a central portion of the hole, and the side surface portion contacts the spherical surface portion.

Abstract: A process cartridge detachably mountable to a main assembly of an electrophotographic image forming apparatus including an openable member movable between a closing position for n opening and an open position for the opening, a guiding member, a main assembly positioning portion, and a main assembly movable member movable in interrelation with the openable member, the cartridge includes an electrophotographic photosensitive member; process means actable on the photosensitive member; a cartridge positioning portion, engageable with the main assembly of the apparatus, for positioning the cartridge relative to the main assembly; a cartridge movable member movable by movement of the main assembly movable member, when the cartridge, upon mounting of the cartridge to the main assembly through the opening while being guided by the guiding member, stops at a position upstream, with respect to a cartridge mounting direction, of an image formation position where the cartridge positioning portion is engaged with the mai

Abstract: A drive transmission apparatus includes a first coupling portion having a polygonal shape; a second coupling portion having a hole portion which has a cross-sectional configuration larger than the first coupling portion, the hole portion being engageable with the first coupling portion; and a center shaft provided on the first coupling or the second coupling, the center shaft penetrating the other one of the first and second coupling.