Abstract: An image forming apparatus, having a motor, a first photosensitive drum, a second photosensitive drum, a first developing roller, a second developing roller, a first cam, a second cam, a first clutch, a second clutch, a first phase sensor, and a controller, is provided. On condition that a triggering condition is satisfied, the controller starts the motor to operate, place the first clutch in a transmittable condition to cause the first developing roller to move for a first separated position, and place the second clutch in a discontinuing condition; and place the second clutch in the transmittable condition to cause the second developing roller to move to the second separated position in one of cases where a predetermined period since the first clutch is placed in the transmittable condition elapses and where the controller receives the separation signal from the first phase sensor before the predetermined period elapses.

Abstract: An image forming apparatus includes a controller configured to, before driving a development motor, obtain a temperature inside a housing from a temperature sensor, determine whether the obtained temperature inside the housing is equal to or lower than a particular temperature, when determining that the temperature inside the housing is higher than the particular temperature, execute a full-speed mode to control the development motor to rotate at a first target speed and control a process motor to rotate at a second target speed, and when determining that the temperature inside the housing is equal to or lower than the particular temperature, execute a low-temperature mode to control the development motor to rotate at a third target speed lower than the first target speed and control the process motor to rotate at the second target speed that is the same as in the full-speed mode.

Abstract: An image-forming apparatus includes a photosensitive drum, a developing roller, a cam, a switching mechanism, a cam follower, and a controller for controlling the switching mechanism to control rotation of the cam. The cam is rotatable to move the developing roller between a contact position in contact with the photosensitive drum and a separated position in separation from the photosensitive drum. To maintain the developing roller at the contact position after being moved from the separated position, the cam is rotated to move the cam follower from a first holding surface to a second holding surface of the cam through a second guide surface, and is stopped rotating to hold the cam follower in contact with a first guide surface of the cam at a position closer to the first holding surface than to the second holding surface.

Abstract: An image forming apparatus, having a casing, a cover, a first motor, a photosensitive drum, a second motor, a developing motor, a clutch, a contact/separation cam, a switching cam, and a controller, is provided. The controller conducts a first process, in which, when the cover is moved from an open position to a closed position, the controller drives the first motor to rotate the photosensitive drum without causing rotation of the developing roller; and a second process, in which, after a lapse of a first period since the controller started driving the first motor, the controller drives the second motor to move the contact/separation cam from the first phase to the second phase and move the switching cam from the first phase to the second phase causing the developing roller to be moved from the contacting position to the separated position while the photosensitive drum is rotating.

Abstract: An image forming apparatus, having first, second, and third photosensitive drums, a first developing cartridge including a first developing roller, a second developing cartridge including a second developing roller, a third developing cartridge including a third developing roller, an exposure device, a conveyer, and a moving mechanism, is provided. The first developing roller, the second developing roller, and the third developing roller are arranged in the recited order from upstream to downstream in a moving direction for the sheet to be conveyed. When the second developing roller is at the separated position thereof, the second developing cartridge coincides with a light path of the laser beam for scanning the first photosensitive drum. When the third developing roller is at the separated position thereof, the third developing cartridge coincides with a light path of the laser beam for scanning the second photosensitive drum.

Abstract: A drum cartridge mountable to an image forming apparatus in a mounting direction, the drum cartridge including: a frame having an opening, the frame allowing a toner cartridge to be attached, and the frame including a housing configured to accommodate therein a toner and a first storage medium including a first electric contact; a photosensitive drum; and a second storage medium including a second electric contact and located at an outer surface of the frame, and in a state where the toner cartridge is mounted to the frame, the first storage medium is exposed via the opening and the second storage medium is aligned with the first storage medium in the mounting direction of the drum cartridge.

Abstract: A drum cartridge mountable to an image forming apparatus in a mounting direction, the drum cartridge including: a frame having an opening, the frame allowing a toner cartridge to be attached, and the frame including a housing configured to accommodate therein a toner and a first storage medium including a first electric contact; a photosensitive drum; and a second storage medium including a second electric contact and located at an outer surface of the frame, and in a state where the toner cartridge is mounted to the frame, the first storage medium is exposed via the opening and the second storage medium is aligned with the first storage medium in the mounting direction of the drum cartridge.

Abstract: An image forming apparatus includes: a housing having an opening; a drum cartridge mountable and demountable through the opening; a toner cartridge mountable and demountable to and from the drum cartridge; a first cover; a second cover, wherein, when the first cover is at the opened position and the second cover is at the closed position, the toner cartridge is allowed to be mounted and demounted to and from the drum cartridge through a part of the opening while the drum cartridge is remained to be mounted to the housing, and wherein, when the first cover is at the opened position and the second cover is at the closed position, a part of the second cover contacts with the drum cartridge and prevents the drum cartridge to be mounted and demounted to and from the housing through a part of the opening.

Abstract: An image forming apparatus, having a first photosensitive drum, a first developing roller, a first shifting member movable between a contacting position and a separating position, a motor, a first joint, a first clutch operable in one of a transmittable condition and a discontinuing condition, a first shifting cam rotatable between a first position, in which the first shifting cam locates the first shifting member at the contacting position, and a second position, in which the first shifting cam locates the first shifting member at the separating position, and a first switching cam rotatable between a third position, in which the first switching cam places the first clutch in the transmittable condition, and a fourth position, in which the first switching cam places the first clutch in the discontinuing condition, alongside the first shifting cam rotating between the first position and the second position, is provided.

Abstract: An image forming apparatus includes: a housing having an opening; a drum cartridge mountable and demountable through the opening; a toner cartridge mountable and demountable to and from the drum cartridge; a first cover; a second cover, wherein, when the first cover is at the opened position and the second cover is at the closed position, the toner cartridge is allowed to be mounted and demounted to and from the drum cartridge through a part of the opening while the drum cartridge is remained to be mounted to the housing, and wherein, when the first cover is at the opened position and the second cover is at the closed position, a part of the second cover contacts with the drum cartridge and prevents the drum cartridge to be mounted and demounted to and from the housing through a part of the opening.

Abstract: An image forming apparatus operable in conjunction with a cartridge having a memory and a terminal, which is electrically connected with the memory and arranged on a downward face of the cartridge, is provided. The image forming apparatus includes a housing having an opening, a controller, and a supporter to support the cartridge at an attachment position. The supporter includes a guiding portion to guide the cartridge there-along and a memory electrode electrically connected with the controller. The guiding portion guides the cartridge being attached to the attachment position to descend as the cartridge approaches from the opening to the attachment position. The memory electrode protrudes upward at a position lower than the terminal on the cartridge and has a height to contact the terminal to electrically connect the controller with the memory when the cartridge is at the attachment position.

Abstract: A drum cartridge mountable to an image forming apparatus in a mounting direction, the drum cartridge including: a frame having an opening, the frame allowing a toner cartridge to be attached, and the frame including a housing configured to accommodate therein a toner and a first storage medium including a first electric contact; a photosensitive drum; and a second storage medium including a second electric contact and located at an outer surface of the frame, and in a state where the toner cartridge is mounted to the frame, the first storage medium is exposed via the opening and the second storage medium is aligned with the first storage medium in the mounting direction of the drum cartridge.

Abstract: An image forming apparatus has a first opening on a side surface of the casing, first and second frames, a cartridge detachably attached through the first opening, and light receiver and light emitter respectively provided to the first and second frames. The cartridge shields the light from the light emitted when attached to an attachment position. The first and second frames face across the attachment position. The light reaches the light receiver when the cartridge is detached from the casing. A door is movably secured to the casing between closing and opening positions, and a second opening allowing a sheet to pass through is formed on the door. External light entering through the second opening and directed toward the light receiver is shielded by a light shielding part provided to the first frame, which also serves as a guiding part to guide attachment of the cartridge.

Abstract: An image forming apparatus includes a photosensitive drum, a light exposure device, a developing device, a fixing unit disposed opposite to the light exposure device relative to the developing device, a sheet supply tray disposed below the developing device, an ejection tray disposed above the developing device and having a sheet receiving surface inclined downward, relative to a horizontal direction, toward the charger, and a sheet conveying path through which a sheet is conveyed from the sheet supply tray to the ejection tray. A lowest end portion of the sheet receiving surface is disposed below an upper end of the charger in the vertical direction. The charger is disposed opposite to the developing device relative to the lowest end portion of the sheet receiving surface.

Abstract: An image forming apparatus includes a photosensitive drum, a light exposure device, a developing device, a fixing unit disposed opposite to the light exposure device relative to the developing device, a sheet supply tray disposed below the developing device, an ejection tray disposed above the developing device and having a sheet receiving surface inclined downward, relative to a horizontal direction, toward the charger, and a sheet conveying path through which a sheet is conveyed from the sheet supply tray to the ejection tray. A lowest end portion of the sheet receiving surface is disposed below an upper end of the charger in the vertical direction. The charger is disposed opposite to the developing device relative to the lowest end portion of the sheet receiving surface.

Abstract: An image forming apparatus has a first opening on a side surface of the casing, first and second frames, a cartridge detachably attached through the first opening, and light receiver and light emitter respectively provided to the first and second frames. The cartridge shields the light from the light emitted when attached to an attachment position. The first and second frames face across the attachment position. The light reaches the light receiver when the cartridge is detached from the casing. A door is movably secured to the casing between closing and opening positions, and a second opening allowing a sheet to pass through is formed on the door. External light entering through the second opening and directed toward the light receiver is shielded by a light shielding part provided to the first frame, which also serves as a guiding part to guide attachment of the cartridge.

Abstract: An image forming apparatus operable in conjunction with a cartridge having a memory and a terminal, which is electrically connected with the memory and arranged on a downward face of the cartridge, is provided. The image forming apparatus includes a housing having an opening, a controller, and a supporter to support the cartridge at an attachment position. The supporter includes a guiding portion to guide the cartridge there-along and a memory electrode electrically connected with the controller. The guiding portion guides the cartridge being attached to the attachment position to descend as the cartridge approaches from the opening to the attachment position. The memory electrode protrudes upward at a position lower than the terminal on the cartridge and has a height to contact the terminal to electrically connect the controller with the memory when the cartridge is at the attachment position.

Abstract: An image forming apparatus includes a photosensitive drum, a light exposure device, a developing device, a fixing unit disposed opposite to the light exposure device relative to the developing device, a sheet supply tray disposed below the developing device, an ejection tray disposed above the developing device and having a sheet receiving surface inclined downward, relative to a horizontal direction, toward the charger, and a sheet conveying path through which a sheet is conveyed from the sheet supply tray to the ejection tray. A lowest end portion of the sheet receiving surface is disposed below an upper end of the charger in the vertical direction. The charger is disposed opposite to the developing device relative to the lowest end portion of the sheet receiving surface.

Abstract: A cartridge of an image forming apparatus includes a conveying member configured to convey toner from a tonner accommodating part of the cartridge to a developing device, and a switching lever configured to switch a state of the conveying member between a driven state and a non-driven state. The toner replenishment lever is movable between a first position at which the replenishment lever pushes the switching lever and a second position at which the replenishment lever is spaced from the switching lever. The contacting part is retracted to outside of a space through which the cartridge passes when attached to or detached from the attachment position. The switching lever is configured to switch the state of the conveying member between the driven state and the non-driven state depending on whether the contacting part of the toner replenishment lever is located at the first position or the second position.

Abstract: An image forming apparatus includes a photosensitive drum, a light exposure device, a developing device, a fixing unit disposed opposite to the light exposure device relative to the developing device, a sheet supply tray disposed below the developing device, an ejection tray disposed above the developing device and having a sheet receiving surface inclined downward, relative to a horizontal direction, toward the charger, and a sheet conveying path through which a sheet is conveyed from the sheet supply tray to the ejection tray. A lowest end portion of the sheet receiving surface is disposed below an upper end of the charger in the vertical direction. The charger is disposed opposite to the developing device relative to the lowest end portion of the sheet receiving surface.