An image-forming apparatus includes first and second photosensitive drums, first and second image-forming portion including first and second development rollers configured to bear developers composed of first and second toner particles and organosilicon protrusions formed on surfaces of the first and second toner particles, an intermediate transfer member to which a developer image is to be transferred in first and second contact portions in contact with the first and second photosensitive drums, and a transfer member configured to transfer the developer image to a recording material in a transfer portion. The first contact portion is formed downstream of the transfer portion and upstream of the second contact portion in a movement direction of the surface of the intermediate transfer member. A protrusion formed on the second developer has a lower height than a protrusion formed on the first developer.

An image forming apparatus includes: a photoconductor; an optical writer to write a latent image on the photoconductor; an image data generator to generate image data of at least one of text and image and of a correction pattern; a light emission controller to control a light source of the optical writer; a developing device to develop the latent image into a toner image; a transfer device to transfer the toner image onto a recording medium; a fixing device to fix the toner image thereon; a detector to detect the toner image of the correction pattern formed according to the image data; and a writing position controller to control when the light source emits light based on the toner image detected. The correction pattern is formed at each of four corners inside a margin of the recording medium, and includes two edges in each of main scanning and sub-scanning directions.

A developing device includes a developing unit, a rotating member that rotates in a predetermined direction to generate an airflow in a space that accommodates the developing unit, and first and second partitioning members. The first partitioning member is disposed between the developing unit and the rotating member, and has first and second openings that are each provided with an opening-closing mechanism and respectively disposed at upstream and downstream sides in a direction of the airflow generated when the rotating member rotates in the predetermined direction. The second partitioning member is disposed between the developing unit and an external space, and has third and fourth openings that are each provided with an opening-closing mechanism and respectively disposed at downstream and upstream sides in the direction of the airflow generated when the rotating member rotates in the predetermined direction.

A developing device includes a developing unit, a rotating member that rotates in a predetermined direction to generate an airflow in a space that accommodates the developing unit, and first and second partitioning members. The first partitioning member is disposed between the developing unit and the rotating member, and has first and second openings that are each provided with an opening-closing mechanism and respectively disposed at upstream and downstream sides in a direction of the airflow generated when the rotating member rotates in the predetermined direction. The second partitioning member is disposed between the developing unit and an external space, and has third and fourth openings that are each provided with an opening-closing mechanism and respectively disposed at downstream and upstream sides in the direction of the airflow generated when the rotating member rotates in the predetermined direction.

A developing cartridge mountable to a development rotary of an electrophotographic image forming apparatus, a coupling member for transmitting a rotational force from a main assembly engaging portion to a developing roller, the coupling member being engageable and disengageable relative to the engaging portion with rotation of the rotary, the coupling member being movable among a rotational force transmitting angular positio, a pre-engagement angular position in which the coupling member is inclined relative to that in the transmitting angular position to engage with the engaging portion, and a disengaging angular position for disengaging therefrom; and an inclination regulating member movable between a regulating position for positioning the coupling member to the pre-engagement position and a retracted position, the inclination regulating member being movable from the retracted position to the regulating position by being abutted by a function member of the rotary.

An image forming apparatus includes an intermediary transfer member; a first image forming portion including a first developing device and a detecting portion; a second image forming portion including a second developing device; a contact-and-separation mechanism capable of setting a first state and a second state; and an executing portion capable of executing an operation in a first monochromatic mode in the first state and capable of executing an operation in a second monochromatic mode in the second state. When a toner amount in the first developing device is below a predetermined amount on the basis of the detecting portion during an image forming operation for continuously forming the black image in the operation in the first monochromatic mode, the executing portion continuously executes the image forming operation in the second state.

A developing cartridge mountable to a development rotary of an electrophotographic image forming apparatus, a coupling member for transmitting a rotational force from a main assembly engaging portion to a developing roller, the coupling member being engageable and disengageable relative to the engaging portion with rotation of the rotary, the coupling member being movable among a rotational force transmitting angular position, a pre-engagement angular position in which the coupling member is inclined relative to that in the transmitting angular position to engage with the engaging portion, and a disengaging angular position for disengaging therefrom; and an inclination regulating member movable between a regulating position for positioning the coupling member to the pre-engagement position and a retracted position, the inclination regulating member being movable from the retracted position to the regulating position by being abutted by a function member of the rotary.

Provided is a development cartridge mounted on a main body of an image forming apparatus. The development cartridge includes a photoconductive unit, a developing unit coupled to the photoconductive unit so as to rotate to a development position and a release position, and an elastic member that provides an elastic force to maintain the developing unit at the development position. A switching member is mounted on a rotation shaft of the developing roller to be rotatable about a rotation shaft of a developing roller. The switching member is switched to a first state where the switching member contacts an interfering portion of the photoconductive unit and rotates the developing unit to the release position and to a second state where the switching member is separated from the interfering portion and allows the developing unit to rotate to the development position due to the elastic force of the elastic member.

A developing device that is useable with an electrophotographic image forming apparatus includes a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum. The developing device also includes a coupling member for transmitting a rotating force to the developing roller.

An image forming apparatus cartridge comprises a guide member, a developer roller having an axis L1, and a coupling member having an axis L2, with the coupling member including at least one projection. A relative positioning of the coupling member and the guide member is changeable between a first relative position in which a tip of the at least one projection is a first distance away from an end of the guide member as measured in the direction of the axis L1 and a second relative position in which the tip of the at least one projection is a second distance away from the end of the guide member as measured in the direction of the axis L1, with the first distance being greater than the second distance.