An image formation apparatus includes an image bearing member on which an electrostatic latent image is formed and a developing agent bearing member configured to carry a developer used to develop the electrostatic latent image formed on the image bearing member. The image formation apparatus forms an image by using the electrostatic latent image formed on the image bearing member. The image formation apparatus further includes an obtaining unit configured to obtain the information about a rotation speed of the image bearing member and a rotation speed of the developing agent bearing member; a determination unit configured to determine, according to the obtained information, a color conversion table used to transfer and record the input image data; and an image formation unit configured to convert a signal of the input image data according to the determined color conversion table and form an image with the converted signal value.

A developing device includes an accommodating member, a developer carrying member, a feeding screw provided with a helical blade, a bearing portion, and a guiding portion including an inclined surface. With respect to the developer feeding direction, a position of an edge of a receiving port of the accommodating member on a bearing portion side is closer to the bearing portion than a mostupstream end of the blade with respect to the developer feeding direction is. With respect to the developer feeding direction, a position of a downstream end portion of the inclined surface is remoter from the bearing portion than the mostupstream end of the blade with respect to the developer feeding direction is.

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.

An image forming apparatus includes: a casing; a toner cartridge; a drum cartridge; a main electrode; a first reading portion; and a controller. The toner cartridge is attachable to the drum cartridge and includes: a developing roller; and a developing electrode electrically connected to the developing roller. The drum cartridge is attachable to the casing and includes: a photosensitive drum; a pressing member; and a drum memory. The pressing member presses the toner cartridge toward the photosensitive drum so that an outer circumferential surface of the developing roller contacts an outer circumferential surface of the photosensitive drum. The drum memory stores a pressing force value indicating a pressing force to be applied by the pressing member. The controller is configured to perform: reading, through the first reading portion, the pressing force value from the drum memory; and applying a voltage to the main electrode based on the pressing force value.

An image forming apparatus includes an image carrier, a developer carrier disposed so as to face the image carrier, a transfer body disposed so as to face the image carrier, and a contact-separation mechanism. The contact-separation mechanism brings the developer carrier and the image carrier into contact with each other and separates the developer carrier and the image carrier from each other, and brings the image carrier and the transfer body into contact with each other and separates the image carrier and the transfer body from each other.

A developing cartridge includes a housing, a storage medium having an electrical contact surface, a holder holding the electrical contact surface and movable with respect to the housing between a first position and a second position, and a roller including a first roller protrusion. The first roller protrusion is movable between a third position and a fourth position in accordance with rotation of the roller. The holder is movable in accordance with movement of the first roller protrusion. As the first roller protrusion moves from the third position to the fourth position, the holder moves from the first position to the second position.

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.

A developing device includes a developing member that develops an electrostatic latent image on an image carrying member with developer; a housing that houses and supports the developing member and has an open part facing the image carrying member; a storage portion provided inside the housing and storing the developer; and a leakage suppressing member provided at an edge of the open part that is on a downstream side in a direction of rotation of the developing member, the leakage suppressing member suppressing leakage of the developer from the housing toward the image carrying member. The housing has an opening on the downstream side in the direction of rotation with respect to the leakage suppressing member and on an upstream side in the direction of rotation with respect to the storage portion, the opening being open from a side of the developing member toward the outside of the housing.

An image forming apparatus includes a developing device including a photosensitive unit having a photoreceptor and a developing unit having a developing. A light scanning unit including a light source may be included to generate light to form an electrostatic latent image on the photoreceptor through a window through which the light is transmitted, and shutter unit may be included to open and close the window. At least one pressing unit is provided to press the developing unit to cause the developing roller separated from the photoreceptor to contact the photoreceptor. The pressing unit may further cause the shutter unit to open and close the window. An operating unit is connected to the at least one pressing unit. The operating unit is movable between an operating position to generate a pressing force by the at least one pressing unit to press the developing unit to contact the photoreceptor and a standby position to release the pressing force.

An image forming apparatus includes an image carrier, a developer carrier disposed so as to face the image carrier, a transfer body disposed so as to face the image carrier, and a contact-separation mechanism. The contact-separation mechanism brings the developer carrier and the image carrier into contact with each other and separates the developer carrier and the image carrier from each other, and brings the image carrier and the transfer body into contact with each other and separates the image carrier and the transfer body from each other.