A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, the developing device being mountable to the movable member, and the developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with the developing device mounted to the movable member, the developing device includes i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis; and ii) a coupling member for transmitting a rotating force to the developing roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller, a pre-engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the driving shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position; wherein in response to a movement of the developing device when the movable member moves in the one direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the one direction from a position where the coupling member is opposed to the driving shaft, in response to the further movement, the coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

A development bias to be applied onto a developing unit is reduced, in a case where it is determined that a remaining amount of toner is equal to or less than a threshold, in a mode in which a rotation speed of a developing unit is faster than a rotation speed of an image bearing member to increase an amount of toner to be supplied to the image bearing member.

An image forming apparatus includes an image forming unit that has multiple developing units, arranged in series for basic colors in a rotational driving direction of a transfer body, for developing toner images of the basic colors based on input image data and forms the overlapped toner images on a surface of the transfer body in a state in which the toner images are aligned; a transferring unit that transfers the toner images onto a sheet; and a controller that calculates a difference between color information of an image obtained by reading the toner images and color information of the input image data, calculates a color change direction of the toner images with respect to a color of the input image data based on the difference, and refers to a table and determines a shape of a surface of the sheet based on information of the color change direction.

A development cartridge for an image forming apparatus includes a photoconductive unit including a photoconductive drum, a developing unit including a developing roller having a rotation shaft and coupled to the photoconductive unit to be rotatable to a release position where the developing roller is separated from the photoconductive drum, and to a development position where the developing roller contacts the photoconductive drum, and a coupler located between and couplable to the rotation shaft of the developing roller and a rotational power transmission member. When the coupler is coupled to the rotational power transmission member, the coupler is selectively rotatable in a first rotation direction or a second rotation direction by a rotational force from the rotational power transmission member. When the coupler is rotated in the first rotation direction and then in the second rotation direction, transmission of the rotational force to the developing roller is partially interrupted.

A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, the developing device being mountable to the movable member, and the developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with the developing device mounted to the movable member, the developing device includes i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis; and ii) a coupling member for transmitting a rotating force to the developing roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller, a pre-engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the driving shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position; wherein in response to a movement of the developing device when the movable member moves in the one direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the one direction from a position where the coupling member is opposed to the driving shaft, in response to the further movement, the coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, the developing device being mountable to the movable member, and the developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with the developing device mounted to the movable member, the developing device includes i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis; and ii) a coupling member for transmitting a rotating force to the developing roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller, a pre-engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the driving shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position; wherein in response to a movement of the developing device when the movable member moves in the one direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the one direction from a position where the coupling member is opposed to the driving shaft, in response to the further movement, the coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, the developing device being mountable to the movable member, and the developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with the developing device mounted to the movable member, the developing device includes i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis; and ii) a coupling member for transmitting a rotating force to the developing roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller, a pre-engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the driving shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position; wherein in response to a movement of the developing device when the movable member moves in the one direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the one direction from a position where the coupling member is opposed to the driving shaft, in response to the further movement, the coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

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.

A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, the developing device being mountable to the movable member, and the developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with the developing device mounted to the movable member, the developing device includes i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis; and ii) a coupling member for transmitting a rotating force to the developing roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller, a pre-engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the driving shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position; wherein in response to a movement of the developing device when the movable member moves in the one direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the one direction from a position where the coupling member is opposed to the driving shaft, in response to the further movement, the coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.

A developing device usable with an electrophotographic image forming apparatus, the apparatus including a driving shaft rotatable by a motor and having a rotating force applying portion, and a movable member, the developing device being mountable to the movable member, and the developing device being movable in a direction substantially perpendicular to an axial direction of the driving shaft in response to movement of the movable member in one direction with the developing device mounted to the movable member, the developing device includes i) a developing roller for developing an electrostatic latent image formed on an electrophotographic photosensitive drum, the developing roller being rotatable about an axis; and ii) a coupling member for transmitting a rotating force to the developing roller, the coupling member including, a rotating force receiving portion engageable with the rotating force applying portion to receive a rotating force from the driving shaft, and a rotating force transmitting portion for transmitting the rotating force received through the rotating force receiving portion to the developing roller, the coupling member being capable of taking a rotational force transmitting angular position for transmitting the rotational force for rotating the developing roller to the developing roller, a pre-engagement angular position which is taken before the coupling member is engaged with the rotating force applying portion and in which the coupling member is inclined away from the rotational force transmitting angular position, and a disengaging angular position which is taken for the coupling member to disengage from the driving shaft and in which the coupling member is inclined away from the rotational force transmitting angular position in a direction opposite to the pre-engagement angular position; wherein in response to a movement of the developing device when the movable member moves in the one direction, the coupling member moves from the pre-engagement angular position to the rotational force transmitting angular position to be opposed to the driving shaft, and wherein when the movable member makes a further movement in the one direction from a position where the coupling member is opposed to the driving shaft, in response to the further movement, the coupling member is disengaged from the driving shaft by moving from the rotational force transmitting angular position to the disengaging angular position.